12 files changed, 474 insertions, 495 deletions

diff --git a/Source/SPCopyTable.m b/Source/SPCopyTable.m
index 212a545c..0fa58711 100644
--- a/Source/SPCopyTable.m
+++ b/Source/SPCopyTable.m
@@ -800,8 +800,8 @@ static const NSInteger kBlobAsImageFile = 4;
 	maxCellWidth = 0;
 	for (i = 0; i < rowsToCheck; i += rowStep) {
 
-		// Retrieve the cell's content
-		contentString = [tableStorage cellDataAtRow:i column:columnIndex];
+		// Retrieve part of the cell's content to get widths, topping out at a maximum length
+		contentString =	SPDataStoragePreviewAtRowAndColumn(tableStorage, i, columnIndex, 500);
 
 		// If the cell hasn't loaded yet, skip processing
 		if (!contentString)
diff --git a/Source/SPCustomQuery.h b/Source/SPCustomQuery.h
index c0e309af..528b8209 100644
--- a/Source/SPCustomQuery.h
+++ b/Source/SPCustomQuery.h
@@ -57,7 +57,7 @@
 @class SPSplitView;
 @class SPFieldEditorController;
 @class SPMySQLConnection;
-@class SPMySQLFastStreamingResult;
+@class SPMySQLStreamingResultStore;
 @class SPTextView;
 
 #ifdef SP_CODA
@@ -162,6 +162,7 @@
 
 	SPDataStorage *resultData;
 	pthread_mutex_t resultDataLock;
+	NSCondition *resultLoadingCondition;
 	NSInteger resultDataCount;
 	NSArray *cqColumnDefinition;
 	NSString *lastExecutedQuery;
@@ -257,7 +258,7 @@
 - (NSArray *)currentResult;
 - (NSArray *)currentDataResultWithNULLs:(BOOL)includeNULLs truncateDataFields:(BOOL)truncate;
 - (NSUInteger)currentResultRowCount;
-- (void)processResultIntoDataStorage:(SPMySQLFastStreamingResult *)theResult;
+- (void)updateResultStore:(SPMySQLStreamingResultStore *)theResultStore;
 
 // Retrieving and setting table state
 - (void)updateTableView;
diff --git a/Source/SPCustomQuery.m b/Source/SPCustomQuery.m
index 686e700b..27fc11c6 100644
--- a/Source/SPCustomQuery.m
+++ b/Source/SPCustomQuery.m
@@ -69,8 +69,7 @@
 
 @interface SPCustomQuery (PrivateAPI)
 
-- (id)_resultDataItemAtRow:(NSInteger)row columnIndex:(NSUInteger)column;
-- (id)_convertResultDataValueToDisplayableRepresentation:(id)value whilePreservingNULLs:(BOOL)preserveNULLs truncateDataFields:(BOOL)truncate;
+- (id)_resultDataItemAtRow:(NSInteger)row columnIndex:(NSUInteger)column preserveNULLs:(BOOL)preserveNULLs asPreview:(BOOL)asPreview;
 + (NSString *)linkToHelpTopic:(NSString *)aTopic;
 
 @end
@@ -581,7 +580,7 @@
 {
 	NSAutoreleasePool	*queryRunningPool = [[NSAutoreleasePool alloc] init];
 	NSArray				*queries	= [taskArguments objectForKey:@"queries"];
-	SPMySQLFastStreamingResult	*streamingResult  = nil;
+	SPMySQLStreamingResultStore	*resultStore  = nil;
 	NSMutableString		*errors     = [NSMutableString string];
 	SEL					callbackMethod = NULL;
 	NSString			*taskButtonString;
@@ -652,8 +651,8 @@
 		[tempQueries addObject:query];
 
 		// Run the query, timing execution (note this also includes network and overhead)
-		streamingResult = [[mySQLConnection streamingQueryString:query] retain];
-		executionTime += [streamingResult queryExecutionTime];
+		resultStore = [[mySQLConnection resultStoreFromQueryString:query] retain];
+		executionTime += [resultStore queryExecutionTime];
 		totalQueriesRun++;
 
 		// If this is the last query, retrieve and store the result; otherwise,
@@ -662,7 +661,7 @@
 
 			// Retrieve and cache the column definitions for the result array
 			if (cqColumnDefinition) [cqColumnDefinition release];
-			cqColumnDefinition = [[streamingResult fieldDefinitions] retain];
+			cqColumnDefinition = [[resultStore fieldDefinitions] retain];
 
 			if(!reloadingExistingResult) {
 				[[self onMainThread] updateTableView];
@@ -683,18 +682,18 @@
 			// Init copyTable with necessary information for copying selected rows as SQL INSERT
 			[customQueryView setTableInstance:self withTableData:resultData withColumns:cqColumnDefinition withTableName:resultTableName withConnection:mySQLConnection];
 
-			[self processResultIntoDataStorage:streamingResult];
+			[self updateResultStore:resultStore];
 		} else {
-			[streamingResult cancelResultLoad];
+			[resultStore cancelResultLoad];
 		}
 
 		// Record any affected rows
 		if ( [mySQLConnection rowsAffectedByLastQuery] != (unsigned long long)~0 )
 			totalAffectedRows += (NSUInteger)[mySQLConnection rowsAffectedByLastQuery];
-		else if ( [streamingResult numberOfRows] )
-			totalAffectedRows += (NSUInteger)[streamingResult numberOfRows];
+		else if ( [resultStore numberOfRows] )
+			totalAffectedRows += (NSUInteger)[resultStore numberOfRows];
 
-		[streamingResult release];
+		[resultStore release];
 
 		// Store any error messages
 		if ([mySQLConnection queryErrored] || [mySQLConnection lastQueryWasCancelled]) {
@@ -804,8 +803,8 @@
 
 	// Perform empty query if no query is given
 	if ( !queryCount ) {
-		streamingResult = [mySQLConnection streamingQueryString:@""];
-		[streamingResult cancelResultLoad];
+		resultStore = [mySQLConnection resultStoreFromQueryString:@""];
+		[resultStore cancelResultLoad];
 		[errors setString:[mySQLConnection lastErrorMessage]];
 	}
 
@@ -944,55 +943,38 @@
 }
 
 /**
- * Processes a supplied streaming result set, loading it into the data array.
+ * Processes a supplied streaming result store, monitoring the load and updating
+ * the data displayed during download.
  */
-- (void)processResultIntoDataStorage:(SPMySQLFastStreamingResult *)theResult
+- (void)updateResultStore:(SPMySQLStreamingResultStore *)theResultStore
 {
-	NSAutoreleasePool *dataLoadingPool;
 
 	// Remove all items from the table
 	resultDataCount = 0;
 	[customQueryView performSelectorOnMainThread:@selector(noteNumberOfRowsChanged) withObject:nil waitUntilDone:YES];
 	pthread_mutex_lock(&resultDataLock);
 	[resultData removeAllRows];
+
+	// Add the new store
+	[resultData setDataStorage:theResultStore updatingExisting:NO];
 	pthread_mutex_unlock(&resultDataLock);
 
-	// Set the column count on the data store before setting up anything else -
-	// ensures that SPDataStorage is set up for timer-driven data loads
-	[resultData setColumnCount:[theResult numberOfFields]];
+	// Start the data downloading
+	[theResultStore startDownload];
 
-	// Set up the table updates timer
+	// Set up the table updates timer and wait for it to notify this thread about completion
 	[[self onMainThread] initQueryLoadTimer];
 
-	// Set up an autorelease pool for row processing
-	dataLoadingPool = [[NSAutoreleasePool alloc] init];
-
-	// Loop through the result rows as they become available
-	for (NSArray *eachRow in theResult) {
-
-		pthread_mutex_lock(&resultDataLock);
-		SPDataStorageAddRow(resultData, eachRow);
-		resultDataCount++;
-		pthread_mutex_unlock(&resultDataLock);
-
-		// Drain and reset the autorelease pool every ~1024 rows
-		if (!(resultDataCount % 1024)) {
-			[dataLoadingPool drain];
-			dataLoadingPool = [[NSAutoreleasePool alloc] init];
-		}
+	[resultLoadingCondition lock];
+	while (![resultData dataDownloaded]) {
+		[resultLoadingCondition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.05]];
 	}
-
-	// Clean up the interface update timer
-	[[self onMainThread] clearQueryLoadTimer];
+	[resultLoadingCondition unlock];
 
 	// If the final column autoresize wasn't performed, perform it
 	if (queryLoadLastRowCount < 200) [[self onMainThread] autosizeColumns];
 
 	[customQueryView performSelectorOnMainThread:@selector(noteNumberOfRowsChanged) withObject:nil waitUntilDone:NO];
-	[customQueryView setNeedsDisplay:YES];
-
-	// Clean up the autorelease pool
-	[dataLoadingPool drain];
 }
 
 /**
@@ -1483,11 +1465,20 @@
  */
 - (void) queryLoadUpdate:(NSTimer *)theTimer
 {
+	resultDataCount = [resultData count];
+
 	if (queryLoadTimerTicksSinceLastUpdate < queryLoadInterfaceUpdateInterval) {
 		queryLoadTimerTicksSinceLastUpdate++;
 		return;
 	}
 
+	if ([resultData dataDownloaded]) {
+		[resultLoadingCondition lock];
+		[resultLoadingCondition signal];
+		[self clearQueryLoadTimer];
+		[resultLoadingCondition unlock];
+	}
+
 	// Check whether a table update is required, based on whether new rows are
 	// available to display.
 	if (resultDataCount == (NSInteger)queryLoadLastRowCount) {
@@ -1496,7 +1487,6 @@
 
 	// Update the table display
 	[customQueryView noteNumberOfRowsChanged];
-	if (!queryLoadLastRowCount) [customQueryView setNeedsDisplay:YES];
 
 	// Update column widths in two cases: on very first rows displayed, and once
 	// more than 200 rows are present.
@@ -1574,9 +1564,7 @@
 		
 		while ((tableColumn = [enumerator nextObject])) 
 		{
-			id value = [self _resultDataItemAtRow:i columnIndex:[[tableColumn identifier] integerValue]];
-			
-			[tempRow addObject:[self _convertResultDataValueToDisplayableRepresentation:value whilePreservingNULLs:includeNULLs truncateDataFields:truncate]];			
+			[tempRow addObject:[self _resultDataItemAtRow:i columnIndex:[[tableColumn identifier] integerValue] preserveNULLs:includeNULLs asPreview:truncate]];
 		}
 		
 		[currentResult addObject:[NSArray arrayWithArray:tempRow]];
@@ -1682,7 +1670,6 @@
 
 		[dataCell setLineBreakMode:NSLineBreakByTruncatingTail];
 		[dataCell setFormatter:[[SPDataCellFormatter new] autorelease]];
-		[[dataCell formatter] setDisplayLimit:150];
 
 		// Set field length limit if field is a varchar to match varchar length
 		if ([[columnDefinition objectForKey:@"typegrouping"] isEqualToString:@"string"]
@@ -2045,7 +2032,7 @@
 		} else {
 #endif
 			// otherwise, just update the data in the data storage
-			SPDataStorageReplaceObjectAtRowAndColumn(resultData, rowIndex, [[aTableColumn identifier] intValue], anObject);
+			[resultData replaceObjectInRow:rowIndex column:[[aTableColumn identifier] intValue] withObject:anObject];
 #ifndef SP_CODA
 		}
 #endif
@@ -2075,35 +2062,34 @@
 {
 	if (aTableView == customQueryView) {
 
+		if (![cell respondsToSelector:@selector(setTextColor:)]) {
+			return;
+		}
+
 		// For NULL cell's display the user's NULL value placeholder in grey to easily distinguish it from other values
-		if ([cell respondsToSelector:@selector(setTextColor:)]) {
-			
-			id value = nil;
-			NSUInteger columnIndex = [[aTableColumn identifier] integerValue];
-
-			// While the table is being loaded, additional validation is required - data
-			// locks must be used to avoid crashes, and indexes higher than the available
-			// rows or columns may be requested.  Use gray to show loading in these cases.
-			if (isWorking) {
-				pthread_mutex_lock(&resultDataLock);
-				
-				if (rowIndex < resultDataCount && columnIndex < [resultData columnCount]) {
-					value = SPDataStorageObjectAtRowAndColumn(resultData, rowIndex, columnIndex);
-				}
-				
-				pthread_mutex_unlock(&resultDataLock);
+		BOOL showCellAsGray = NO;
 
-				if (!value) {
-					[cell setTextColor:[NSColor lightGrayColor]];
-					return;
-				}
-			} 
-			else {
-				value = SPDataStorageObjectAtRowAndColumn(resultData, rowIndex, columnIndex);
+		NSUInteger columnIndex = [[aTableColumn identifier] integerValue];
+
+		// While the table is being loaded, additional validation is required - data
+		// locks must be used to avoid crashes, and indexes higher than the available
+		// rows or columns may be requested.  Use gray to show loading in these cases.
+		if (isWorking) {
+			pthread_mutex_lock(&resultDataLock);
+				
+			if (rowIndex < resultDataCount && columnIndex < [resultData columnCount]) {
+				showCellAsGray = [resultData cellIsNullOrUnloadedAtRow:rowIndex column:columnIndex];
+			} else {
+				showCellAsGray = YES;
 			}
 
-			[cell setTextColor:[value isNSNull] ? [NSColor lightGrayColor] : [NSColor blackColor]];
+			pthread_mutex_unlock(&resultDataLock);
 		}
+		else {
+			showCellAsGray = [resultData cellIsNullOrUnloadedAtRow:rowIndex column:columnIndex];
+		}
+
+		[cell setTextColor:showCellAsGray ? [NSColor lightGrayColor] : [NSColor blackColor]];
 	}
 }
 
@@ -2113,8 +2099,7 @@
 - (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)tableColumn row:(NSInteger)rowIndex
 {
 	if (aTableView == customQueryView) {
-		
-		return [self _convertResultDataValueToDisplayableRepresentation:[self _resultDataItemAtRow:rowIndex columnIndex:[[tableColumn identifier] integerValue]] whilePreservingNULLs:NO truncateDataFields:YES];
+		return [self _resultDataItemAtRow:rowIndex columnIndex:[[tableColumn identifier] integerValue] preserveNULLs:NO asPreview:YES];
 	}
 
 	return @"";
@@ -3768,6 +3753,7 @@
 		runPrimaryActionButtonAsSelection = nil;
 
 		queryLoadTimer = nil;
+		resultLoadingCondition = [NSCondition new];
 
 		prefs = [NSUserDefaults standardUserDefaults];
 
@@ -3988,12 +3974,13 @@
 /**
  * Retrieves the value from the underlying data storage at the supplied row and column indices.
  *
- * @param row    The row index
- * @param column The column index
+ * @param row           The row index
+ * @param column        The column index
+ * @param preserveNULLs Whether t
  * 
  * @return The value from the data storage
  */
-- (id)_resultDataItemAtRow:(NSInteger)row columnIndex:(NSUInteger)column
+- (id)_resultDataItemAtRow:(NSInteger)row columnIndex:(NSUInteger)column preserveNULLs:(BOOL)preserveNULLs asPreview:(BOOL)asPreview;
 {
 	id value = nil;
 	
@@ -4005,7 +3992,11 @@
 		pthread_mutex_lock(&resultDataLock);
 		
 		if (row < resultDataCount && column < [resultData columnCount]) {
-			value = [[SPDataStorageObjectAtRowAndColumn(resultData, row, column) copy] autorelease];
+			if (asPreview) {
+				value = SPDataStoragePreviewAtRowAndColumn(resultData, row, column, 150);
+			} else {
+				value = SPDataStorageObjectAtRowAndColumn(resultData, row, column);
+			}
 		}
 		
 		pthread_mutex_unlock(&resultDataLock);
@@ -4013,36 +4004,23 @@
 		if (!value) value = @"...";
 	} 
 	else {
-		value = SPDataStorageObjectAtRowAndColumn(resultData, row, column);
+		if (asPreview) {
+			value = SPDataStoragePreviewAtRowAndColumn(resultData, row, column, 150);
+		} else {
+			value = SPDataStorageObjectAtRowAndColumn(resultData, row, column);
+		}
 	}
-	
-	return value;
-}
 
-/**
- * Converts the supplied value into it's displayable representation.
- *
- * @param value         The value to convert
- * @param preserveNULLs Whether or not NULLs should be preserved or converted to the 
- *                      user's NULL placeholder preference.
- * @param truncate      Whether or not data fields should be truncates for display purposes.
- *
- * @return The converted value
- */
-- (id)_convertResultDataValueToDisplayableRepresentation:(id)value whilePreservingNULLs:(BOOL)preserveNULLs truncateDataFields:(BOOL)truncate
-{
+	if ([value isKindOfClass:[SPMySQLGeometryData class]])
+		return [value wktString];
+
+	if ([value isNSNull])
+		return preserveNULLs ? value : [prefs objectForKey:SPNullValue];
+
 	if ([value isKindOfClass:[NSData class]]) {
-		value = truncate ? [value shortStringRepresentationUsingEncoding:[mySQLConnection stringEncoding]] : [value stringRepresentationUsingEncoding:[mySQLConnection stringEncoding]]; 
+		return [value stringRepresentationUsingEncoding:[mySQLConnection stringEncoding]];
 	}
-	
-	if ([value isNSNull] && !preserveNULLs) {
-		value = [prefs objectForKey:SPNullValue];
-	}
-	
-	if ([value isKindOfClass:[SPMySQLGeometryData class]]) {
-		value = [value wktString];
-	}
-	
+
 	return value;
 }
 
@@ -4057,6 +4035,7 @@
 	[NSObject cancelPreviousPerformRequestsWithTarget:customQueryView];
 
 	[self clearQueryLoadTimer];
+	[resultLoadingCondition release];
 	[usedQuery release];
 	[lastExecutedQuery release];
 	[resultData release];
diff --git a/Source/SPDataCellFormatter.h b/Source/SPDataCellFormatter.h
index d1f9c7d4..00cc85bb 100644
--- a/Source/SPDataCellFormatter.h
+++ b/Source/SPDataCellFormatter.h
@@ -33,12 +33,10 @@
 @interface SPDataCellFormatter : NSFormatter 
 {
 	NSInteger textLimit;
-	NSUInteger displayLimit;
 	NSString *fieldType;
 }
 
 @property (readwrite, assign) NSInteger textLimit;
-@property (readwrite, assign) NSUInteger displayLimit;
 @property (readwrite, retain) NSString* fieldType;
 
 @end
diff --git a/Source/SPDataCellFormatter.m b/Source/SPDataCellFormatter.m
index 951fafbc..616e59db 100644
--- a/Source/SPDataCellFormatter.m
+++ b/Source/SPDataCellFormatter.m
@@ -36,24 +36,10 @@
 @implementation SPDataCellFormatter
 
 @synthesize textLimit;
-@synthesize displayLimit;
 @synthesize fieldType;
 
-- (id)init
-{
-	if ((self = [super init])) {
-		displayLimit = NSNotFound;
-	}
-	return self;
-}
-
 - (NSString *)stringForObjectValue:(id)anObject
 {
-	// Truncate the string for speed purposes if it's very long - improves table scrolling speed.
-	if (displayLimit != NSNotFound && [anObject isKindOfClass:[NSString class]] && [(NSString *)anObject length] > displayLimit) {
-		return ([NSString stringWithFormat:@"%@...", [anObject substringToIndex:displayLimit - 3]]);
-	}
-
 	if (![anObject isKindOfClass:[NSString class]]) {
 		return [anObject description];
 	}
diff --git a/Source/SPDataStorage.h b/Source/SPDataStorage.h
index 39d36d5f..d0c1f556 100644
--- a/Source/SPDataStorage.h
+++ b/Source/SPDataStorage.h
@@ -30,45 +30,54 @@
 //
 //  More info at <http://code.google.com/p/sequel-pro/>
 
+#import <SPMySQL/SPMySQLStreamingResultStoreDelegate.h>
+
+@class SPMySQLStreamingResultStore;
+
 /**
- * This class provides a storage mechanism intended to represent tabular
- * data, in a 2D array.  Data can be added and retrieved either directly
- * or via NSArrays; internally, C arrays are used to provide speed and
- * memory improvements.
- * This class is essentially mutable.
+ * This class wraps a SPMySQLStreamingResultStore, providing an editable
+ * data store; on a fresh load all data will be proxied from the underlying
+ * result store, but if cells or rows are edited, mutable rows are stored
+ * directly.
  */
 
-@interface SPDataStorage : NSObject 
+@interface SPDataStorage : NSObject <SPMySQLStreamingResultStoreDelegate>
 {
-	NSUInteger numColumns;
-	NSUInteger columnPointerByteSize;
-	NSUInteger numRows, numRowsCapacity;
+	SPMySQLStreamingResultStore *dataStorage;
+	NSPointerArray *editedRows;
+	BOOL *unloadedColumns;
 
-	id **dataStorage;
+	NSUInteger numberOfColumns;
 }
 
+/* Setting result store */
+- (void) setDataStorage:(SPMySQLStreamingResultStore *) newDataStorage updatingExisting:(BOOL)updateExistingStore;
+
 /* Retrieving rows and cells */
-- (NSMutableArray *) rowContentsAtIndex:(NSUInteger)index;
+- (NSMutableArray *) rowContentsAtIndex:(NSUInteger)anIndex;
 - (id) cellDataAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex;
+- (id) cellPreviewAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex previewLength:(NSUInteger)previewLength;
+- (BOOL) cellIsNullOrUnloadedAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex;
 
 /* Adding and amending rows and cells */
-- (void) addRowWithContents:(NSArray *)row;
-- (void) insertRowContents:(NSArray *)row atIndex:(NSUInteger)index;
-- (void) replaceRowAtIndex:(NSUInteger)index withRowContents:(NSArray *)row;
-- (void) replaceObjectInRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex withObject:(id)object;
-- (void) removeRowAtIndex:(NSUInteger)index;
+- (void) addRowWithContents:(NSMutableArray *)aRow;
+- (void) insertRowContents:(NSMutableArray *)aRow atIndex:(NSUInteger)anIndex;
+- (void) replaceRowAtIndex:(NSUInteger)anIndex withRowContents:(NSMutableArray *)aRow;
+- (void) replaceObjectInRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex withObject:(id)anObject;
+- (void) removeRowAtIndex:(NSUInteger)anIndex;
 - (void) removeRowsInRange:(NSRange)rangeToRemove;
 - (void) removeAllRows;
 
+/* Unloaded columns */
+- (void) setColumnAsUnloaded:(NSUInteger)columnIndex;
+
 /* Basic information */
 - (NSUInteger) count;
-- (void) setColumnCount:(NSUInteger)columnCount;
 - (NSUInteger) columnCount;
+- (BOOL) dataDownloaded;
 
-/* Initialisation and teardown */
-#pragma mark -
-- (id) init;
-- (void) dealloc;
+/* Delegate callback methods */
+- (void)resultStoreDidFinishLoadingData:(SPMySQLStreamingResultStore *)resultStore;
 
 @end
 
@@ -91,14 +100,6 @@ static inline void SPDataStorageReplaceRow(SPDataStorage* self, NSUInteger rowIn
 	SPDSReplaceRow(self, @selector(replaceRowAtIndex:withRowContents:), rowIndex, row);
 }
 
-static inline void SPDataStorageReplaceObjectAtRowAndColumn(SPDataStorage* self, NSUInteger rowIndex, NSUInteger colIndex, id newObject) 
-{
-	typedef void (*SPDSObjectReplaceMethodPtr)(SPDataStorage*, SEL, NSUInteger, NSUInteger, id);
-	static SPDSObjectReplaceMethodPtr SPDSObjectReplace;
-	if (!SPDSObjectReplace) SPDSObjectReplace = (SPDSObjectReplaceMethodPtr)[self methodForSelector:@selector(replaceObjectInRow:column:withObject:)];
-	SPDSObjectReplace(self, @selector(replaceObjectInRow:column:withObject:), rowIndex, colIndex, newObject);
-}
-
 static inline id SPDataStorageObjectAtRowAndColumn(SPDataStorage* self, NSUInteger rowIndex, NSUInteger colIndex) 
 {
 	typedef id (*SPDSObjectFetchMethodPtr)(SPDataStorage*, SEL, NSUInteger, NSUInteger);
@@ -106,3 +107,12 @@ static inline id SPDataStorageObjectAtRowAndColumn(SPDataStorage* self, NSUInteg
 	if (!SPDSObjectFetch) SPDSObjectFetch = (SPDSObjectFetchMethodPtr)[self methodForSelector:@selector(cellDataAtRow:column:)];
 	return SPDSObjectFetch(self, @selector(cellDataAtRow:column:), rowIndex, colIndex);
 }
+
+static inline id SPDataStoragePreviewAtRowAndColumn(SPDataStorage* self, NSUInteger rowIndex, NSUInteger colIndex, NSUInteger previewLength)
+{
+	typedef id (*SPDSPreviewFetchMethodPtr)(SPDataStorage*, SEL, NSUInteger, NSUInteger, NSUInteger);
+	static SPDSPreviewFetchMethodPtr SPDSPreviewFetch;
+	if (!SPDSPreviewFetch) SPDSPreviewFetch = (SPDSPreviewFetchMethodPtr)[self methodForSelector:@selector(cellPreviewAtRow:column:previewLength:)];
+	return SPDSPreviewFetch(self, @selector(cellPreviewAtRow:column:previewLength:), rowIndex, colIndex, previewLength);
+}
+
diff --git a/Source/SPDataStorage.m b/Source/SPDataStorage.m
index 1b3d1cba..c2119032 100644
--- a/Source/SPDataStorage.m
+++ b/Source/SPDataStorage.m
@@ -31,45 +31,89 @@
 //  More info at <http://code.google.com/p/sequel-pro/>
 
 #import "SPDataStorage.h"
+#import "SPObjectAdditions.h"
+#import <SPMySQL/SPMySQLStreamingResultStore.h>
 
-@interface SPDataStorage (PrivateAPI)
+@interface SPDataStorage (Private_API)
 
-- (void) _ensureCapacityForAdditionalRowCount:(NSUInteger)numExtraRows;
-- (void) _increaseCapacity;
+- (void) _checkNewRow:(NSMutableArray *)aRow;
 
 @end
 
 @implementation SPDataStorage
 
-static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorage* self, NSUInteger numExtraRows) 
+static inline NSMutableArray* SPDataStorageGetEditedRow(NSPointerArray* rowStore, NSUInteger rowIndex)
 {
-	typedef void (*SPDSEnsureCapacityMethodPtr)(SPDataStorage*, SEL, NSUInteger);
-	static SPDSEnsureCapacityMethodPtr SPDSEnsureCapacity;
-	if (!SPDSEnsureCapacity) SPDSEnsureCapacity = (SPDSEnsureCapacityMethodPtr)[self methodForSelector:@selector(_ensureCapacityForAdditionalRowCount:)];
-	SPDSEnsureCapacity(self, @selector(_ensureCapacityForAdditionalRowCount:), numExtraRows);
+	typedef NSMutableArray* (*SPDSGetEditedRowMethodPtr)(NSPointerArray*, SEL, NSUInteger);
+	static SPDSGetEditedRowMethodPtr SPDSGetEditedRow;
+	if (!SPDSGetEditedRow) SPDSGetEditedRow = (SPDSGetEditedRowMethodPtr)[rowStore methodForSelector:@selector(pointerAtIndex:)];
+	return SPDSGetEditedRow(rowStore, @selector(pointerAtIndex:), rowIndex);
 }
 
+#pragma mark - Setting result store
+
+/**
+ * Set the underlying MySQL data storage.
+ * This will clear all edited rows and unloaded column tracking.
+ */
+- (void) setDataStorage:(SPMySQLStreamingResultStore *)newDataStorage updatingExisting:(BOOL)updateExistingStore
+{
+	NSUInteger i;
+	[editedRows release], editedRows = nil;
+	if (unloadedColumns) free(unloadedColumns), unloadedColumns = NULL;
+
+	if (dataStorage) {
+
+		// If the table is reloading data, link to the current data store for smoother loads
+		if (updateExistingStore) {
+			[newDataStorage replaceExistingResultStore:dataStorage];
+		}
+
+		[dataStorage release], dataStorage = nil;
+	}
+
+	dataStorage = [newDataStorage retain];
+	[dataStorage setDelegate:self];
+
+	numberOfColumns = [dataStorage numberOfFields];
+	editedRows = [NSPointerArray new];
+	if ([dataStorage dataDownloaded]) {
+		[self resultStoreDidFinishLoadingData:dataStorage];
+	}
+
+	unloadedColumns = malloc(numberOfColumns * sizeof(BOOL));
+	for (i = 0; i < numberOfColumns; i++) {
+		unloadedColumns[i] = NO;
+	}
+}
+
+
 #pragma mark -
 #pragma mark Retrieving rows and cells
 
 /**
  * Return a mutable array containing the data for a specified row.
  */
-- (NSMutableArray *) rowContentsAtIndex:(NSUInteger)index
+- (NSMutableArray *) rowContentsAtIndex:(NSUInteger)anIndex
 {
 
-	// Throw an exception if the index is out of bounds
-	if (index >= numRows) [NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)index, (unsigned long long)numRows];
+	// If an edited row exists for the supplied index, return it
+	NSMutableArray *editedRow = SPDataStorageGetEditedRow(editedRows, anIndex);
+	if (editedRow != NULL) {
+		return editedRow;
+	}
 
-	// Construct the NSMutableArray
-	NSMutableArray *rowArray = [NSMutableArray arrayWithCapacity:numColumns];
-	id *row = dataStorage[index];
-	NSUInteger i;
-	for (i = 0; i < numColumns; i++) {
-		CFArrayAppendValue((CFMutableArrayRef)rowArray, row[i]);
+	// Otherwise, prepare to return the underlying storage row
+	NSMutableArray *dataArray = SPMySQLResultStoreGetRow(dataStorage, anIndex);
+
+	// Modify unloaded cells as appropriate
+	for (NSUInteger i = 0; i < numberOfColumns; i++) {
+		if (unloadedColumns[i]) {
+			CFArraySetValueAtIndex((CFMutableArrayRef)dataArray, i, [SPNotLoaded notLoaded]);
+		}
 	}
 
-	return rowArray;
+	return dataArray;
 }
 
 /**
@@ -78,11 +122,78 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
 - (id) cellDataAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex
 {
 
-	// Throw an exception if the row or column index is out of bounds
-	if (rowIndex >= numRows || columnIndex >= numColumns) [NSException raise:NSRangeException format:@"Requested storage index (row %llu, col %llu) beyond bounds (%llu, %llu)", (unsigned long long)rowIndex, (unsigned long long)columnIndex, (unsigned long long)numRows, (unsigned long long)numColumns];
+	// If an edited row exists at the supplied index, return it
+	NSMutableArray *editedRow = SPDataStorageGetEditedRow(editedRows, rowIndex);
+	if (editedRow != NULL) {
+		return CFArrayGetValueAtIndex((CFArrayRef)editedRow, columnIndex);
+	}
+
+	// Throw an exception if the column index is out of bounds
+	if (columnIndex >= numberOfColumns) {
+		[NSException raise:NSRangeException format:@"Requested storage column (col %llu) beyond bounds (%llu)", (unsigned long long)columnIndex, (unsigned long long)numberOfColumns];
+	}
+
+	// If the specified column is not loaded, return a SPNotLoaded reference
+	if (unloadedColumns[columnIndex]) {
+		return [SPNotLoaded notLoaded];
+	}
 
 	// Return the content
-	return dataStorage[rowIndex][columnIndex];
+	return SPMySQLResultStoreObjectAtRowAndColumn(dataStorage, rowIndex, columnIndex);
+}
+
+/**
+ * Return a preview of the data at a specified row and column index, limited
+ * to approximately the supplied length.
+ */
+- (id) cellPreviewAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex previewLength:(NSUInteger)previewLength
+{
+
+	// If an edited row exists at the supplied index, return it
+	NSMutableArray *editedRow = SPDataStorageGetEditedRow(editedRows, rowIndex);
+	if (editedRow != NULL) {
+		id anObject = CFArrayGetValueAtIndex((CFArrayRef)editedRow, columnIndex);
+		if ([anObject isKindOfClass:[NSString class]] && [(NSString *)anObject length] > 150) {
+			return ([NSString stringWithFormat:@"%@...", [anObject substringToIndex:147]]);
+		}
+		return anObject;
+	}
+
+	// Throw an exception if the column index is out of bounds
+	if (columnIndex >= numberOfColumns) {
+		[NSException raise:NSRangeException format:@"Requested storage column (col %llu) beyond bounds (%llu)", (unsigned long long)columnIndex, (unsigned long long)numberOfColumns];
+	}
+
+	// If the specified column is not loaded, return a SPNotLoaded reference
+	if (unloadedColumns[columnIndex]) {
+		return [SPNotLoaded notLoaded];
+	}
+
+	// Return the content
+	return SPMySQLResultStorePreviewAtRowAndColumn(dataStorage, rowIndex, columnIndex, previewLength);
+}
+
+/**
+ * Returns whether the data at a specified row and column index is NULL or unloaded
+ */
+- (BOOL) cellIsNullOrUnloadedAtRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex
+{
+	// If an edited row exists at the supplied index, check it for a NULL.
+	NSMutableArray *editedRow = SPDataStorageGetEditedRow(editedRows, rowIndex);
+	if (editedRow != NULL) {
+		return [(id)CFArrayGetValueAtIndex((CFArrayRef)editedRow, columnIndex) isNSNull];
+	}
+
+	// Throw an exception if the column index is out of bounds
+	if (columnIndex >= numberOfColumns) {
+		[NSException raise:NSRangeException format:@"Requested storage column (col %llu) beyond bounds (%llu)", (unsigned long long)columnIndex, (unsigned long long)numberOfColumns];
+	}
+
+	if (unloadedColumns[columnIndex]) {
+		return YES;
+	}
+
+	return [dataStorage cellIsNullAtRow:rowIndex column:columnIndex];
 }
 
 #pragma mark -
@@ -90,38 +201,37 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
 
 /**
  * Implementation of the NSFastEnumeration protocol.
- * Note that this currently doesn't implement mutation guards.
+ * Note that rows are currently retrieved individually to avoid mutation and locking issues,
+ * although this could be improved on.
  */
 - (NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(id *)stackbuf count:(NSUInteger)len
 {
 
 	// If the start index is out of bounds, return 0 to indicate end of results
-	if (state->state >= numRows) return 0;
-
-	// Determine how many objects to return - 128, len, or all items remaining
-	NSUInteger itemsToReturn = 128;
-	if (len < 128) itemsToReturn = len;
-	if (numRows - state->state < itemsToReturn) {
-		itemsToReturn = numRows - state->state;
-	}
-
-	// Construct the arrays to return
-	NSUInteger i, j;
-	NSMutableArray *rowArray;
-	id *row;
-	for (i = 0; i < itemsToReturn; i++) {
-		row = dataStorage[state->state + i];
-		rowArray = [NSMutableArray arrayWithCapacity:numColumns];
-		for (j = 0; j < numColumns; j++) {
-			CFArrayAppendValue((CFMutableArrayRef)rowArray, row[j]);
+	if (state->state >= SPMySQLResultStoreGetRowCount(dataStorage)) return 0;
+
+	// If an edited row exists for the supplied index, use that; otherwise use the underlying
+	// storage row
+	NSMutableArray *targetRow = SPDataStorageGetEditedRow(editedRows, state->state);
+	if (targetRow == NULL) {
+		targetRow = SPMySQLResultStoreGetRow(dataStorage, state->state);
+
+		// Modify unloaded cells as appropriate
+		for (NSUInteger i = 0; i < numberOfColumns; i++) {
+			if (unloadedColumns[i]) {
+				CFArraySetValueAtIndex((CFMutableArrayRef)targetRow, i, [SPNotLoaded notLoaded]);
+			}
 		}
-		stackbuf[i] = rowArray;
 	}
 
-	state->state += itemsToReturn;
+	// Add the item to the buffer and return the appropriate state
+	stackbuf[0] = targetRow;
+
+	state->state += 1;
 	state->itemsPtr = stackbuf;
-	state->mutationsPtr = (unsigned long *)&numRows;
-	return itemsToReturn;
+	state->mutationsPtr = (unsigned long *)self;
+
+	return 1;
 }
 
 #pragma mark -
@@ -132,29 +242,17 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
  * of objects.  Note that the supplied objects are retained as a reference
  * rather than copied.
  */
-- (void) addRowWithContents:(NSArray *)row
+- (void) addRowWithContents:(NSMutableArray *)aRow
 {
-	
-	// Ensure that sufficient capacity is available
-	SPDataStorageEnsureCapacityForAdditionalRowCount(self, 1);
-
-	// Add an empty row array to the data store
-	id *newRow = (id *)malloc(columnPointerByteSize);
-	dataStorage[numRows] = newRow;
-	numRows++;
-
-	// Copy over references to the array contents, and retain the objects
-	NSUInteger cellsCopied = 0;
-	for (id cellData in row) {
-		if (cellData) newRow[cellsCopied] = (id)CFRetain(cellData);
-		else newRow[cellsCopied] = nil;
-		if (++cellsCopied == numColumns) break;
-	}
 
-	// If an array shorter than the row width was added, pad with nils
-	if (cellsCopied < numColumns) {
-		for ( ; cellsCopied <= numColumns; cellsCopied++) newRow[cellsCopied] = nil;
-	}
+	// Verify the row is of the correct length
+	[self _checkNewRow:aRow];
+
+	// Add the new row to the editable store
+	[editedRows addPointer:aRow];
+
+	// Update the underlying store as well to keep counts correct
+	[dataStorage addDummyRow];
 }
 
 /**
@@ -162,109 +260,70 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
  * all later rows the next index.  Note that the supplied objects within the
  * array are retained as a reference rather than copied.
  */
-- (void) insertRowContents:(NSArray *)row atIndex:(NSUInteger)index
+- (void) insertRowContents:(NSMutableArray *)aRow atIndex:(NSUInteger)anIndex
 {
+	unsigned long long numberOfRows = SPMySQLResultStoreGetRowCount(dataStorage);
+
+	// Verify the row is of the correct length
+	[self _checkNewRow:aRow];
 
 	// Throw an exception if the index is out of bounds
-	if (index > numRows) [NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)index, (unsigned long long)numRows];
+	if (anIndex > numberOfRows) {
+		[NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)anIndex, numberOfRows];
+	}
 
 	// If "inserting" at the end of the array just add a row
-	if (index == numRows) return SPDataStorageAddRow(self, row);
-
-	// Ensure that sufficient capacity is available to hold all the rows
-	SPDataStorageEnsureCapacityForAdditionalRowCount(self, 1);
-
-	// Renumber the specified index, and all subsequent indices, to create a gap
-	for (NSUInteger j = numRows - 1; j >= index; j--) {
-		dataStorage[j + 1] = dataStorage[j];
+	if (anIndex == numberOfRows) {
+		return [self addRowWithContents:aRow];
 	}
 
-	// Add a new instantiated row array to the data store at the specified point
-	id *newRow = (id *)malloc(columnPointerByteSize);
-	dataStorage[index] = newRow;
-	numRows++;
-
-	// Copy over references to the array contents, and retain the objects
-	NSUInteger cellsCopied = 0;
-	for (id cellData in row) {
-		if (cellData) newRow[cellsCopied] = (id)CFRetain(cellData);
-		else newRow[cellsCopied] = nil;
-		if (++cellsCopied == numColumns) break;
-	}
+	// Add the new row to the editable store
+	[editedRows insertPointer:aRow atIndex:anIndex];
 
-	// If an array shorter than the row width was inserted, pad with nils
-	if (cellsCopied < numColumns) {
-		for ( ; cellsCopied <= numColumns; cellsCopied++) newRow[cellsCopied] = nil;
-	}
+	// Update the underlying store to keep counts and indices correct
+	[dataStorage insertDummyRowAtIndex:anIndex];
 }
 
 /**
  * Replace a row with contents of the supplied NSArray.
  */
-- (void) replaceRowAtIndex:(NSUInteger)index withRowContents:(NSArray *)row
+- (void) replaceRowAtIndex:(NSUInteger)anIndex withRowContents:(NSMutableArray *)aRow
 {
-	NSUInteger cellsProcessed = 0;
-
-	// Throw an exception if the index is out of bounds
-	if (index >= numRows) [NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)index, (unsigned long long)numRows];
-
-	id *storageRow = dataStorage[index];
-
-	// Iterate through the row replacing the objects
-	for (id cellData in row) {
-		if (storageRow[cellsProcessed]) CFRelease(storageRow[cellsProcessed]);
-		if (cellData) storageRow[cellsProcessed] = (id)CFRetain(cellData);
-		else storageRow[cellsProcessed] = nil;
-		if (++cellsProcessed == numColumns) break;
-	}
-
-	// Ensure all cells are correctly updated if an array shorter than the row width was supplied
-	if (cellsProcessed < numColumns) {
-		for ( ; cellsProcessed <= numColumns; cellsProcessed++) {
-			if (storageRow[cellsProcessed]) CFRelease(storageRow[cellsProcessed]);
-			storageRow[cellsProcessed] = nil;
-		}
-	}
+	[self _checkNewRow:aRow];
+	[editedRows replacePointerAtIndex:anIndex withPointer:aRow];
 }
 
 /**
  * Replace the contents of a single cell with a supplied object.
  */
-- (void) replaceObjectInRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex withObject:(id)object
+- (void) replaceObjectInRow:(NSUInteger)rowIndex column:(NSUInteger)columnIndex withObject:(id)anObject
 {
 
-	// Throw an exception of either index is out of bounds
-	if (rowIndex >= numRows || columnIndex >= numColumns) [NSException raise:NSRangeException format:@"Requested storage index (row %llu, col %llu) beyond bounds (%llu, %llu)", (unsigned long long)rowIndex, (unsigned long long)columnIndex, (unsigned long long)numRows, (unsigned long long)numColumns];
+	// Make sure that the row in question is editable
+	NSMutableArray *editableRow = SPDataStorageGetEditedRow(editedRows, rowIndex);
+	if (editableRow == NULL) {
+		editableRow = [self rowContentsAtIndex:rowIndex];
+		[editedRows replacePointerAtIndex:rowIndex withPointer:editableRow];
+	}
 
-	// Release the old object and retain the new one
-	if (dataStorage[rowIndex][columnIndex]) CFRelease(dataStorage[rowIndex][columnIndex]);
-	if (object) dataStorage[rowIndex][columnIndex] = (id)CFRetain(object);
-	else dataStorage[rowIndex][columnIndex] = nil;
+	// Modify the cell
+	[editableRow replaceObjectAtIndex:columnIndex withObject:anObject];
 }
 
 /**
  * Remove a row, renumbering all elements beyond index.
  */
-- (void) removeRowAtIndex:(NSUInteger)index
+- (void) removeRowAtIndex:(NSUInteger)anIndex
 {
 
 	// Throw an exception if the index is out of bounds
-	if (index >= numRows) [NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)index, (unsigned long long)numRows];
-
-	// Free the row
-	NSUInteger j = numColumns;
-	id *row = dataStorage[index];
-	while (j > 0) {
-		if (row[--j]) CFRelease(row[j]);
+	if (anIndex >= SPMySQLResultStoreGetRowCount(dataStorage)) {
+		[NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)anIndex, SPMySQLResultStoreGetRowCount(dataStorage)];
 	}
-	free(row);
-	numRows--;
 
-	// Renumber all subsequent indices to fill the gap
-	for (j = index; j < numRows; j++) {
-		dataStorage[j] = dataStorage[j + 1];
-	}
-	dataStorage[numRows] = NULL;
+	// Remove the row from the edited list and underlying storage
+	[editedRows removePointerAtIndex:anIndex];
+	[dataStorage removeRowAtIndex:anIndex];
 }
 
 /**
@@ -275,27 +334,16 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
 {
 
 	// Throw an exception if the range is out of bounds
-	if (rangeToRemove.location + rangeToRemove.length > numRows) [NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)(rangeToRemove.location + rangeToRemove.length), (unsigned long long)numRows];
-
-	// Free rows in the range
-	NSUInteger i, j = numColumns;
-	id *row;
-	for (i = rangeToRemove.location; i < rangeToRemove.location + rangeToRemove.length; i++) {
-		row = dataStorage[i];
-		while (j > 0) {
-			if (row[--j]) CFRelease(row[j]);
-		}
-		free(row);	
+	if (rangeToRemove.location + rangeToRemove.length > SPMySQLResultStoreGetRowCount(dataStorage)) {
+		[NSException raise:NSRangeException format:@"Requested storage index (%llu) beyond bounds (%llu)", (unsigned long long)(rangeToRemove.location + rangeToRemove.length), SPMySQLResultStoreGetRowCount(dataStorage)];
 	}
-	numRows -= rangeToRemove.length;
 
-	// Renumber all subsequent indices to fill the gap
-	for (i = rangeToRemove.location + rangeToRemove.length - 1; i < numRows; i++) {
-		dataStorage[i] = dataStorage[i + rangeToRemove.length];
-	}
-	for (i = numRows; i < numRows + rangeToRemove.length; i++) {
-		dataStorage[i] = NULL;
+	// Remove the rows from the edited list and underlying storage
+	NSUInteger i = rangeToRemove.location + rangeToRemove.length;
+	while (--i >= rangeToRemove.location) {
+		[editedRows removePointerAtIndex:i];
 	}
+	[dataStorage removeRowsInRange:rangeToRemove];
 }
 
 /**
@@ -303,81 +351,58 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
  */
 - (void) removeAllRows
 {
-	NSUInteger j;
-	id *row;
-
-	// Free all the data
-	while (numRows > 0) {
-		row = dataStorage[--numRows];
-		j = numColumns;
-		while (j > 0) {
-			if (row[--j]) CFRelease(row[j]);
-		}
-		free(row);
-	}
+	[editedRows setCount:0];
+	[dataStorage removeAllRows];
+}
 
-	numRows = 0;
+#pragma mark - Unloaded columns
+
+/**
+ * Mark a column as unloaded; SPNotLoaded placeholders will be returned for cells requested
+ * from this store which haven't had their value updated from elsewhere.
+ */
+- (void) setColumnAsUnloaded:(NSUInteger)columnIndex
+{
+	if (columnIndex >= numberOfColumns) {
+		[NSException raise:NSRangeException format:@"Invalid column set as unloaded; requested column index (%llu) beyond bounds (%llu)", (unsigned long long)columnIndex, (unsigned long long)numberOfColumns];
+	}
+	unloadedColumns[columnIndex] = true;
 }
 
-#pragma mark -
-#pragma mark Basic information
+#pragma mark - Basic information
 
 /**
  * Returns the number of rows currently held in data storage.
  */
 - (NSUInteger) count
 {
-	return numRows;
+	return (NSUInteger)[dataStorage numberOfRows];
 }
 
 /**
- * Set the number of columns represented by the data storage.
+ * Return the number of columns represented by the data storage.
  */
-- (void) setColumnCount:(NSUInteger)columnCount
+- (NSUInteger) columnCount
 {
-	columnPointerByteSize = columnCount * sizeof(id);
-
-	// If there are rows present in the storage, and the number of
-	// columns has changed, amend the existing rows to match.
-	if (columnCount != numColumns && numRows) {
-		NSUInteger i = numRows, j;
-		id *row;
-
-		// If the new column count is higher than the old count, iterate through the existing rows
-		// and pad with nils
-		if (columnCount > numColumns) {
-			while (i-- > 0) {
-				dataStorage[i] = (id *)realloc(dataStorage[i], columnPointerByteSize);
-				j = numColumns;
-				while (j < columnCount) {
-					dataStorage[i][j++] = nil;
-				}
-			}
-
-		// If the new column count is lower than the old count, iterate through the existing rows
-		// freeing any extra objects
-		} else {
-			while (i > 0) {
-				row = dataStorage[--i];
-				j = numColumns;
-				while (j > columnCount) {
-					if (row[--j]) CFRelease(row[j]);
-				}
-				dataStorage[i] = (id *)realloc(row, columnPointerByteSize);
-			}
-		}
-	}
+	return numberOfColumns;
+}
 
-	// Update the column count
-	numColumns = columnCount;
+/**
+ * Return whether all the data has been downloaded into the underlying result store.
+ */
+- (BOOL) dataDownloaded
+{
+	return [dataStorage dataDownloaded];
 }
 
+#pragma mark - Delegate callback methods
+
 /**
- * Return the number of columns represented by the data storage.
+ * When the underlying result store finishes downloading, update the row store to match
  */
-- (NSUInteger) columnCount
+- (void)resultStoreDidFinishLoadingData:(SPMySQLStreamingResultStore *)resultStore
 {
-	return numColumns;
+	[editedRows setCount:(NSUInteger)[resultStore numberOfRows]];
 }
 
 /**
@@ -387,20 +412,20 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
 
 - (id) init {
 	if ((self = [super init])) {
-		numColumns = 0;
-		columnPointerByteSize = 0;
-		numRows = 0;
+		dataStorage = nil;
+		editedRows = nil;
+		unloadedColumns = NULL;
 
-		// Initialise the array, initially with space for 100 rows
-		numRowsCapacity = 100;
-		dataStorage = (id **)malloc(numRowsCapacity * sizeof(id *));
+		numberOfColumns = 0;
 	}
 	return self;
 }
 
 - (void) dealloc {
-	[self removeAllRows];
-	free(dataStorage);
+	[dataStorage release], dataStorage = nil;
+	[editedRows release], editedRows = nil;
+	if (unloadedColumns) free(unloadedColumns), unloadedColumns = NULL;
+
 	[super dealloc];
 }
 
@@ -408,23 +433,12 @@ static inline void SPDataStorageEnsureCapacityForAdditionalRowCount(SPDataStorag
 
 @implementation SPDataStorage (PrivateAPI)
 
-/**
- * Private method to ensure the array always has sufficient capacity
- * to store any additional rows required.
- */
-- (void) _ensureCapacityForAdditionalRowCount:(NSUInteger)numExtraRows
+- (void) _checkNewRow:(NSMutableArray *)aRow
 {
-	while (numRows + numExtraRows > numRowsCapacity) [self _increaseCapacity];
+	if ([aRow count] != numberOfColumns) {
+		[NSException raise:NSInternalInconsistencyException format:@"New row length (%llu) does not match store column	count (%llu)", (unsigned long long)[aRow count], (unsigned long long)numberOfColumns];
+	}
 }
 
-/**
- * Private method to increase the storage available for the array;
- * currently doubles the capacity as boundaries are reached.
- */
-- (void) _increaseCapacity
-{
-	numRowsCapacity *= 2;
-	dataStorage = (id **)realloc(dataStorage, numRowsCapacity * sizeof(id *));
-}
 
 @end
diff --git a/Source/SPPreferencesUpgrade.m b/Source/SPPreferencesUpgrade.m
index af639191..55e68157 100644
--- a/Source/SPPreferencesUpgrade.m
+++ b/Source/SPPreferencesUpgrade.m
@@ -65,11 +65,15 @@ void SPApplyRevisionChanges(void)
 	if ([prefs objectForKey:SPLastUsedVersion]) recordedVersionNumber = [[prefs objectForKey:SPLastUsedVersion] integerValue];
 
 	// Skip processing if the current version matches or is less than recorded version
-	if (currentVersionNumber <= recordedVersionNumber) return;
+	if (currentVersionNumber <= recordedVersionNumber) {
+		[importantUpdateNotes release];
+		return;
+	}
 	
 	// If no recorded version, update to current revision and skip processing
 	if (!recordedVersionNumber) {
 		[prefs setObject:[NSNumber numberWithInteger:currentVersionNumber] forKey:SPLastUsedVersion];
+		[importantUpdateNotes release];
 		return;
 	}
 
diff --git a/Source/SPTableContent.h b/Source/SPTableContent.h
index cb81a706..ab62b87f 100644
--- a/Source/SPTableContent.h
+++ b/Source/SPTableContent.h
@@ -40,7 +40,7 @@
 @class SPTextView;
 @class SPFieldEditorController;
 @class SPMySQLConnection;
-@class SPMySQLFastStreamingResult;
+@class SPMySQLStreamingResultStore;
 @class SPTableData;
 @class SPDatabaseDocument;
 @class SPTablesList;
@@ -118,6 +118,7 @@
 	BOOL _mainNibLoaded;
 	BOOL isWorking;
 	pthread_mutex_t tableValuesLock;
+	NSCondition *tableLoadingCondition;
 #ifndef SP_CODA
 	NSMutableArray *nibObjectsToRelease;
 #endif
@@ -261,7 +262,7 @@
 - (void)clickLinkArrow:(SPTextAndLinkCell *)theArrowCell;
 - (void)clickLinkArrowTask:(SPTextAndLinkCell *)theArrowCell;
 - (IBAction)setCompareTypes:(id)sender;
-- (void)processResultIntoDataStorage:(SPMySQLFastStreamingResult *)theResult approximateRowCount:(NSUInteger)targetRowCount;
+- (void)updateResultStore:(SPMySQLStreamingResultStore *)theResultStore approximateRowCount:(NSUInteger)targetRowCount;
 - (BOOL)saveRowToTable;
 - (void) addRowErrorSheetDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo;
 - (NSString *)argumentForRow:(NSInteger)row;
diff --git a/Source/SPTableContent.m b/Source/SPTableContent.m
index f093f875..cc0102f2 100644
--- a/Source/SPTableContent.m
+++ b/Source/SPTableContent.m
@@ -72,6 +72,12 @@
 static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOperator";
 #endif
 
+@interface SPTableContent (SPTableContentDataSource_Private_API)
+
+- (id)_contentValueForTableColumn:(NSUInteger)columnIndex row:(NSUInteger)rowIndex asPreview:(BOOL)asPreview;
+
+@end
+
 @interface SPTableContent ()
 
 - (BOOL)cancelRowEditing;
@@ -165,6 +171,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 		usedQuery = [[NSString alloc] initWithString:@""];
 
 		tableLoadTimer = nil;
+		tableLoadingCondition = [NSCondition new];
 
 		blackColor = [NSColor blackColor];
 		lightGrayColor = [NSColor lightGrayColor];
@@ -609,10 +616,9 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 
 		[dataCell setEditable:YES];
 
-		// Set the line break mode and an NSFormatter subclass which truncates long strings for display
+		// Set the line break mode and an NSFormatter subclass which displays line breaks nicely
 		[dataCell setLineBreakMode:NSLineBreakByTruncatingTail];
 		[dataCell setFormatter:[[SPDataCellFormatter new] autorelease]];
-		[[dataCell formatter] setDisplayLimit:150];
 
 		// Set field length limit if field is a varchar to match varchar length
 		if ([[columnDefinition objectForKey:@"typegrouping"] isEqualToString:@"string"]
@@ -765,7 +771,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 	NSMutableString *queryString;
 	NSString *queryStringBeforeLimit = nil;
 	NSString *filterString;
-	SPMySQLFastStreamingResult *streamingResult;
+	SPMySQLStreamingResultStore *resultStore;
 	NSInteger rowsToLoad = [[tableDataInstance statusValueForKey:@"Rows"] integerValue];
 
 #ifndef SP_CODA
@@ -828,23 +834,23 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 	// Perform and process the query
 	[tableContentView performSelectorOnMainThread:@selector(noteNumberOfRowsChanged) withObject:nil waitUntilDone:YES];
 	[self setUsedQuery:queryString];
-	streamingResult = [[mySQLConnection streamingQueryString:queryString] retain];
+	resultStore = [[mySQLConnection resultStoreFromQueryString:queryString] retain];
 
 	// Ensure the number of columns are unchanged; if the column count has changed, abort the load
 	// and queue a full table reload.
 	BOOL fullTableReloadRequired = NO;
-	if (streamingResult && [dataColumns count] != [streamingResult numberOfFields]) {
+	if (resultStore && [dataColumns count] != [resultStore numberOfFields]) {
 		[tableDocumentInstance disableTaskCancellation];
 		[mySQLConnection cancelCurrentQuery];
-		[streamingResult cancelResultLoad];
+		[resultStore cancelResultLoad];
 		fullTableReloadRequired = YES;
 	}
 
 	// Process the result into the data store
-	if (!fullTableReloadRequired && streamingResult) {
-		[self processResultIntoDataStorage:streamingResult approximateRowCount:rowsToLoad];
+	if (!fullTableReloadRequired && resultStore) {
+		[self updateResultStore:resultStore approximateRowCount:rowsToLoad];
 	}
-	if (streamingResult) [streamingResult release];
+	if (resultStore) [resultStore release];
 
 	// If the result is empty, and a late page is selected, reset the page
 	if (!fullTableReloadRequired && [prefs boolForKey:SPLimitResults] && queryStringBeforeLimit && !tableRowsCount && ![mySQLConnection lastQueryWasCancelled]) {
@@ -852,10 +858,10 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 		previousTableRowsCount = tableRowsCount;
 		queryString = [NSMutableString stringWithFormat:@"%@ LIMIT 0,%ld", queryStringBeforeLimit, (long)[prefs integerForKey:SPLimitResultsValue]];
 		[self setUsedQuery:queryString];
-		streamingResult = [[mySQLConnection streamingQueryString:queryString] retain];
-		if (streamingResult) {
-			[self processResultIntoDataStorage:streamingResult approximateRowCount:[prefs integerForKey:SPLimitResultsValue]];
-			[streamingResult release];
+		resultStore = [[mySQLConnection resultStoreFromQueryString:queryString] retain];
+		if (resultStore) {
+			[self updateResultStore:resultStore approximateRowCount:[prefs integerForKey:SPLimitResultsValue]];
+			[resultStore release];
 		}
 	}
 
@@ -950,7 +956,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 
 	// Retrieve and cache the column definitions for editing views
 	if (cqColumnDefinition) [cqColumnDefinition release];
-	cqColumnDefinition = [[streamingResult fieldDefinitions] retain];
+	cqColumnDefinition = [[resultStore fieldDefinitions] retain];
 
 
 	// Notify listenters that the query has finished
@@ -985,100 +991,57 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 }
 
 /**
- * Processes a supplied streaming result set, loading it into the data array.
+ * Processes a supplied streaming result store, monitoring the load and updating the data
+ * displayed during download.
  */
-- (void)processResultIntoDataStorage:(SPMySQLFastStreamingResult *)theResult approximateRowCount:(NSUInteger)targetRowCount
+- (void)updateResultStore:(SPMySQLStreamingResultStore *)theResultStore approximateRowCount:(NSUInteger)targetRowCount;
 {
 	NSUInteger i;
 	NSUInteger dataColumnsCount = [dataColumns count];
-	BOOL *columnBlobStatuses = malloc(dataColumnsCount * sizeof(BOOL));
 	tableLoadTargetRowCount = targetRowCount;
 
-	// Set the column count on the data store before setting up anything else -
-	// ensures that SPDataStorage is set up for timer-driven data loads
-	[tableValues setColumnCount:dataColumnsCount];
+	// Update the data storage, updating the current store if appropriate
+	pthread_mutex_lock(&tableValuesLock);
+	[tableValues setDataStorage:theResultStore updatingExisting:!![tableValues count]];
+	pthread_mutex_unlock(&tableValuesLock);
 
-	// Set up the table updates timer
-	[[self onMainThread] initTableLoadTimer];
+	// Start the data downloading
+	[theResultStore startDownload];
 
-	NSAutoreleasePool *dataLoadingPool;
 #ifndef SP_CODA
 	NSProgressIndicator *dataLoadingIndicator = [tableDocumentInstance valueForKey:@"queryProgressBar"];
 #else
 	NSProgressIndicator *dataLoadingIndicator = [tableDocumentInstance queryProgressBar];
 #endif
-	BOOL prefsLoadBlobsAsNeeded = 
-#ifndef SP_CODA
-		[prefs boolForKey:SPLoadBlobsAsNeeded]
-#else
-		NO
-#endif
-	;
-	
-	// Build up an array of which columns are blobs for faster iteration
-	for ( i = 0; i < dataColumnsCount ; i++ ) {
-		columnBlobStatuses[i] = [tableDataInstance columnIsBlobOrText:[NSArrayObjectAtIndex(dataColumns, i) objectForKey:@"name"]];
-	}
-
-	// Set up an autorelease pool for row processing
-	dataLoadingPool = [[NSAutoreleasePool alloc] init];
 
-	// Loop through the result rows as they become available
-	tableRowsCount = 0;
-	for (NSArray *eachRow in theResult) {
-		pthread_mutex_lock(&tableValuesLock);
-
-		if (tableRowsCount < previousTableRowsCount) {
-			SPDataStorageReplaceRow(tableValues, tableRowsCount, eachRow);
-		} else {
-			SPDataStorageAddRow(tableValues, eachRow);
-		}
-
-		// Alter the values for hidden blob and text fields if appropriate
-		if ( prefsLoadBlobsAsNeeded ) {
-			for ( i = 0 ; i < dataColumnsCount ; i++ ) {
-				if (columnBlobStatuses[i]) {
-					SPDataStorageReplaceObjectAtRowAndColumn(tableValues, tableRowsCount, i, [SPNotLoaded notLoaded]);
-				}
+#ifndef SP_CODA
+	// Set the column load states on the table values store
+	if ([prefs boolForKey:SPLoadBlobsAsNeeded]) {
+		for ( i = 0; i < dataColumnsCount ; i++ ) {
+			if ([tableDataInstance columnIsBlobOrText:[NSArrayObjectAtIndex(dataColumns, i) objectForKey:@"name"]]) {
+				[tableValues setColumnAsUnloaded:i];
 			}
 		}
-		tableRowsCount++;
+	}
+#endif
 
-		pthread_mutex_unlock(&tableValuesLock);
+	// Set up the table updates timer and wait for it to notify this thread about completion
+	[[self onMainThread] initTableLoadTimer];
 
-		// Drain and reset the autorelease pool every ~1024 rows
-		if (!(tableRowsCount % 1024)) {
-			[dataLoadingPool drain];
-			dataLoadingPool = [[NSAutoreleasePool alloc] init];
-		}
+	[tableLoadingCondition lock];
+	while (![tableValues dataDownloaded]) {
+		[tableLoadingCondition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.05]];
 	}
-
-	// Clean up the interface update timer
-	[[self onMainThread] clearTableLoadTimer];
+	[tableLoadingCondition unlock];
 
 	// If the final column autoresize wasn't performed, perform it
 	if (tableLoadLastRowCount < 200) [[self onMainThread] autosizeColumns];
 
-	// If the reloaded table is shorter than the previous table, remove the extra values from the storage
-	if (tableRowsCount < [tableValues count]) {
-		pthread_mutex_lock(&tableValuesLock);
-		[tableValues removeRowsInRange:NSMakeRange(tableRowsCount, [tableValues count] - tableRowsCount)];
-		pthread_mutex_unlock(&tableValuesLock);
-	}
-
 	// Ensure the table is aware of changes
-	if ([NSThread isMainThread]) {
-		[tableContentView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:YES];
-	} else {
-		[tableContentView performSelectorOnMainThread:@selector(noteNumberOfRowsChanged) withObject:nil waitUntilDone:YES];
-		[tableContentView performSelectorOnMainThread:@selector(reloadData) withObject:nil waitUntilDone:NO];
-	}
+	[[tableContentView onMainThread] noteNumberOfRowsChanged];
 
-	// Clean up the autorelease pool and reset the progress indicator
-	[dataLoadingPool drain];
+	// Reset the progress indicator
 	[dataLoadingIndicator setIndeterminate:YES];
-
-	free(columnBlobStatuses);
 }
 
 /**
@@ -1397,6 +1360,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
  */
 - (void) tableLoadUpdate:(NSTimer *)theTimer
 {
+	tableRowsCount = [tableValues count];
 
 	// Update the task interface as necessary
 	if (!isFiltered && tableLoadTargetRowCount != NSUIntegerMax) {
@@ -1414,6 +1378,13 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 		return;
 	}
 
+	if ([tableValues dataDownloaded]) {
+		[tableLoadingCondition lock];
+		[tableLoadingCondition signal];
+		[self clearTableLoadTimer];
+		[tableLoadingCondition unlock];
+	}
+
 	// Check whether a table update is required, based on whether new rows are
 	// available to display.
 	if (tableRowsCount == tableLoadLastRowCount) {
@@ -1422,7 +1393,6 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 
 	// Update the table display
 	[tableContentView noteNumberOfRowsChanged];
-	if (!tableLoadLastRowCount) [tableContentView setNeedsDisplay:YES];
 
 	// Update column widths in two cases: on very first rows displayed, and once
 	// more than 200 rows are present.
@@ -2452,7 +2422,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 		
 		for (NSTableColumn *tableColumn in tableColumns) 
 		{
-			[tempRow addObject:[self tableView:tableContentView objectValueForTableColumn:tableColumn row:i]];
+			[tempRow addObject:[self _contentValueForTableColumn:[[tableColumn identifier] integerValue] row:i asPreview:NO]];
 		}
 		
 		[currentResult addObject:[NSArray arrayWithArray:tempRow]];
@@ -4274,6 +4244,7 @@ static NSString *SPTableFilterSetDefaultOperator = @"SPTableFilterSetDefaultOper
 	if(fieldEditor) [fieldEditor release], fieldEditor = nil;
 
 	[self clearTableLoadTimer];
+	[tableLoadingCondition release];
 	[tableValues release];
 	pthread_mutex_destroy(&tableValuesLock);
 	[dataColumns release];
diff --git a/Source/SPTableContentDataSource.m b/Source/SPTableContentDataSource.m
index c49169a0..8ffa2c69 100644
--- a/Source/SPTableContentDataSource.m
+++ b/Source/SPTableContentDataSource.m
@@ -39,6 +39,12 @@
 #import <pthread.h>
 #import <SPMySQL/SPMySQL.h>
 
+@interface SPTableContent (SPTableContentDataSource_Private_API)
+
+- (id)_contentValueForTableColumn:(NSUInteger)columnIndex row:(NSUInteger)rowIndex asPreview:(BOOL)asPreview;
+
+@end
+
 @implementation SPTableContent (SPTableContentDataSource)
 
 #pragma mark -
@@ -91,7 +97,7 @@
 				pthread_mutex_lock(&tableValuesLock);
 				
 				if (rowIndex < (NSInteger)tableRowsCount && columnIndex < [tableValues columnCount]) {
-					value = [[SPDataStorageObjectAtRowAndColumn(tableValues, rowIndex, columnIndex) copy] autorelease];
+					value = [self _contentValueForTableColumn:columnIndex row:rowIndex asPreview:YES];
 				}
 				
 				pthread_mutex_unlock(&tableValuesLock);
@@ -99,7 +105,11 @@
 				if (!value) return @"...";
 			} 
 			else {
-				value = SPDataStorageObjectAtRowAndColumn(tableValues, rowIndex, columnIndex);
+				if ([tableView editedColumn] == (NSInteger)columnIndex && [tableView editedRow] == rowIndex) {
+					value = [self _contentValueForTableColumn:columnIndex row:rowIndex asPreview:NO];
+				} else {
+					value = [self _contentValueForTableColumn:columnIndex row:rowIndex asPreview:YES];
+				}
 			}
 			
 			if ([value isKindOfClass:[SPMySQLGeometryData class]])
@@ -185,3 +195,15 @@
 }
 
 @end
+
+@implementation SPTableContent (SPTableContentDataSource_Private_API)
+
+- (id)_contentValueForTableColumn:(NSUInteger)columnIndex row:(NSUInteger)rowIndex asPreview:(BOOL)asPreview
+{
+	if (asPreview) {
+		return SPDataStoragePreviewAtRowAndColumn(tableValues, rowIndex, columnIndex, 150);
+	}
+	return SPDataStorageObjectAtRowAndColumn(tableValues, rowIndex, columnIndex);
+}
+
+@end
diff --git a/Source/SPTableContentDelegate.m b/Source/SPTableContentDelegate.m
index d2e7f2d5..8f228aa0 100644
--- a/Source/SPTableContentDelegate.m
+++ b/Source/SPTableContentDelegate.m
@@ -464,9 +464,18 @@
 			
 			if (![cell respondsToSelector:@selector(setTextColor:)]) return;
 			
-			id theValue = nil;
+			BOOL showCellAsGray = NO;
 			NSUInteger columnIndex = [[tableColumn identifier] integerValue];
 			
+			// If user wants to edit 'cell' set text color to black and return to avoid
+			// writing in gray if value was NULL
+			if ([tableView editedColumn] != -1
+				&& [tableView editedRow] == rowIndex
+				&& (NSUInteger)[[NSArrayObjectAtIndex([tableView tableColumns], [tableView editedColumn]) identifier] integerValue] == columnIndex) {
+				[cell setTextColor:blackColor];
+				return;
+			}
+
 			// While the table is being loaded, additional validation is required - data
 			// locks must be used to avoid crashes, and indexes higher than the available
 			// rows or columns may be requested.  Use gray to indicate loading in these cases.
@@ -474,34 +483,18 @@
 				pthread_mutex_lock(&tableValuesLock);
 				
 				if (rowIndex < (NSInteger)tableRowsCount && columnIndex < [tableValues columnCount]) {
-					theValue = SPDataStorageObjectAtRowAndColumn(tableValues, rowIndex, columnIndex);
+					showCellAsGray = [tableValues cellIsNullOrUnloadedAtRow:rowIndex column:columnIndex];
 				}
 				
 				pthread_mutex_unlock(&tableValuesLock);
-				
-				if (!theValue) {
-					[cell setTextColor:[NSColor lightGrayColor]];
-					return;
-				}
 			} 
 			else {
-				theValue = SPDataStorageObjectAtRowAndColumn(tableValues, rowIndex, columnIndex);
+				showCellAsGray = [tableValues cellIsNullOrUnloadedAtRow:rowIndex column:columnIndex];
 			}
 			
-			// If user wants to edit 'cell' set text color to black and return to avoid
-			// writing in gray if value was NULL
-			if ([tableView editedColumn] != -1
-				&& [tableView editedRow] == rowIndex
-				&& (NSUInteger)[[NSArrayObjectAtIndex([tableView tableColumns], [tableView editedColumn]) identifier] integerValue] == columnIndex) {
-				[cell setTextColor:blackColor];
-				return;
-			}
 			
-			// For null cells and not loaded cells, display the contents in gray.
-			if ([theValue isNSNull] || [theValue isSPNotLoaded]) {
+			if (showCellAsGray) {
 				[cell setTextColor:lightGrayColor];
-				
-				// Otherwise, set the color to black - required as NSTableView reuses NSCells.
 			} 
 			else {
 				[cell setTextColor:blackColor];