/** Close our index ScanController. */
private void closeIndexSC() throws StandardException {
/* Only consider closing index SC if we own it. */
if (ownIndexSC && indexSC != null) {
indexSC.close();
indexSC = null;
}
}
/**
* Delete a row from our index. This assumes our index ScanController is positioned before the row
* by setScan if we own the SC, otherwise it is positioned on the row by the underlying index
* scan.
*
* <p>This verifies the row exists and is unique.
*
* @exception StandardException Thrown on error
*/
private void doDelete() throws StandardException {
if (ownIndexSC) {
if (!indexSC.next()) {
// This means that the entry for the index does not exist, this
// is a serious problem with the index. Past fixed problems
// like track 3703 can leave db's in the field with this problem
// even though the bug in the code which caused it has long
// since been fixed. Then the problem can surface months later
// when the customer attempts to upgrade. By "ignoring" the
// missing row here the problem is automatically "fixed" and
// since the code is trying to delete the row anyway it doesn't
// seem like such a bad idea. It also then gives a tool to
// support to be able to fix some system catalog problems where
// they can delete the base rows by dropping the system objects
// like stored statements.
/*
dem 2013/04/10 - temporarily comment this out while
we are getting snapshot isolation DDL support in
place
if (SanityManager.DEBUG)
SanityManager.THROWASSERT(
"Index row "+RowUtil.toString(ourIndexRow)+
" not found in conglomerateid " + indexCID +
"Current scan = " + indexSC);
*/
Object[] args = new Object[2];
args[0] = ourIndexRow.getRowArray()[ourIndexRow.getRowArray().length - 1];
args[1] = new Long(indexCID);
Monitor.getStream()
.println(
MessageService.getCompleteMessage(
SQLState.LANG_IGNORE_MISSING_INDEX_ROW_DURING_DELETE, args));
// just return indicating the row has been deleted.
return;
}
}
indexSC.delete();
}
/**
* Position our index scan to 'ourIndexRow'.
*
* <p>This creates the scan the first time it is called.
*
* @exception StandardException Thrown on error
*/
private void setScan() throws StandardException {
/*
* -sf- Derby makes an assumption about system tables that isn't true
* for Splice land, which results in WriteConflicts occurring
* when you try to drop tables
*
* With indices, Derby only ever creates start and stop keys for the scan.
* However, if the entire index is to be scanned, one or more column in the start/stop
* key may be null. With db this was apparently treated acceptably, but in Splice
* this results in garbage start and stop row keys, which in turn results in deleting
* every row in the index instead of deleting just the rows of interest.
*
* Thus, the following hack. When the row is not entirely filled, we convert
* the start/stop key into a single ANDed equals qualifier[], and use that instead
*/
DataValueDescriptor[] ourRowDvds = ourIndexRow.getRowArray();
int numNonNull = ourRowDvds.length;
for (int i = 0; i < ourRowDvds.length; i++) {
if (ourRowDvds[i].isNull()) {
numNonNull--;
}
}
Qualifier[][] qualifiers = null;
if (numNonNull < ourRowDvds.length) {
qualifiers = new Qualifier[1][];
qualifiers[0] = new Qualifier[numNonNull];
for (int dvdPos = 0, qualPos = 0; dvdPos < ourRowDvds.length; dvdPos++) {
if (ourRowDvds[dvdPos].isNull()) continue;
ScanQualifier qualifier = new GenericScanQualifier();
qualifier.setQualifier(
dvdPos, ourRowDvds[dvdPos], DataValueDescriptor.ORDER_OP_EQUALS, false, false, false);
qualifiers[0][qualPos] = qualifier;
}
}
/* Get the SC from the activation if re-using */
if (!ownIndexSC) {
indexSC = activation.getIndexScanController();
} else if (indexSC == null) {
RowLocation templateBaseRowLocation = baseCC.newRowLocationTemplate();
/* DataDictionary doesn't have compiled info */
if (indexSCOCI == null) {
indexSC =
tc.openScan(
indexCID,
false, /* hold */
TransactionController.OPENMODE_FORUPDATE, /* forUpdate */
lockMode,
isolationLevel,
(FormatableBitSet) null, /* all fields */
ourIndexRow.getRowArray(), /* startKeyValue */
ScanController.GE, /* startSearchOp */
qualifiers, /* qualifier */
ourIndexRow.getRowArray(), /* stopKeyValue */
ScanController.GT /* stopSearchOp */);
} else {
indexSC =
tc.openCompiledScan(
false, /* hold */
TransactionController.OPENMODE_FORUPDATE, /* forUpdate */
lockMode,
isolationLevel,
(FormatableBitSet) null, /* all fields */
ourIndexRow.getRowArray(), /* startKeyValue */
ScanController.GE, /* startSearchOp */
qualifiers, /* qualifier */
ourIndexRow.getRowArray(), /* stopKeyValue */
ScanController.GT, /* stopSearchOp */
indexSCOCI,
indexDCOCI);
}
} else {
indexSC.reopenScan(
ourIndexRow.getRowArray(), /* startKeyValue */
ScanController.GE, /* startSearchOperator */
qualifiers, /* qualifier */
ourIndexRow.getRowArray(), /* stopKeyValue */
ScanController.GT /* stopSearchOperator */);
}
}
