/**
* Make a ConstraintDescriptor out of a SYSCONSTRAINTS row
*
* @param row a SYSCONSTRAINTS row
* @param parentTupleDescriptor Subconstraint descriptor with auxiliary info.
* @param dd dataDictionary
* @exception StandardException thrown on failure
*/
public TupleDescriptor buildDescriptor(
ExecRow row, TupleDescriptor parentTupleDescriptor, DataDictionary dd)
throws StandardException {
ConstraintDescriptor constraintDesc = null;
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
row.nColumns() == SYSCONSTRAINTS_COLUMN_COUNT,
"Wrong number of columns for a SYSCONSTRAINTS row");
}
DataValueDescriptor col;
ConglomerateDescriptor conglomDesc;
DataDescriptorGenerator ddg;
TableDescriptor td = null;
int constraintIType = -1;
int[] keyColumns = null;
UUID constraintUUID;
UUID schemaUUID;
UUID tableUUID;
UUID referencedConstraintId = null;
SchemaDescriptor schema;
String tableUUIDString;
String constraintName;
String constraintSType;
String constraintStateStr;
boolean constraintEnabled;
int referenceCount;
String constraintUUIDString;
String schemaUUIDString;
SubConstraintDescriptor scd;
if (SanityManager.DEBUG) {
if (!(parentTupleDescriptor instanceof SubConstraintDescriptor)) {
SanityManager.THROWASSERT(
"parentTupleDescriptor expected to be instanceof "
+ "SubConstraintDescriptor, not "
+ parentTupleDescriptor.getClass().getName());
}
}
scd = (SubConstraintDescriptor) parentTupleDescriptor;
ddg = dd.getDataDescriptorGenerator();
/* 1st column is CONSTRAINTID (UUID - char(36)) */
col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTID);
constraintUUIDString = col.getString();
constraintUUID = getUUIDFactory().recreateUUID(constraintUUIDString);
/* 2nd column is TABLEID (UUID - char(36)) */
col = row.getColumn(SYSCONSTRAINTS_TABLEID);
tableUUIDString = col.getString();
tableUUID = getUUIDFactory().recreateUUID(tableUUIDString);
/* Get the TableDescriptor.
* It may be cached in the SCD,
* otherwise we need to go to the
* DD.
*/
if (scd != null) {
td = scd.getTableDescriptor();
}
if (td == null) {
td = dd.getTableDescriptor(tableUUID);
}
/* 3rd column is NAME (varchar(128)) */
col = row.getColumn(SYSCONSTRAINTS_CONSTRAINTNAME);
constraintName = col.getString();
/* 4th column is TYPE (char(1)) */
col = row.getColumn(SYSCONSTRAINTS_TYPE);
constraintSType = col.getString();
if (SanityManager.DEBUG) {
SanityManager.ASSERT(constraintSType.length() == 1, "Fourth column type incorrect");
}
boolean typeSet = false;
switch (constraintSType.charAt(0)) {
case 'P':
constraintIType = DataDictionary.PRIMARYKEY_CONSTRAINT;
typeSet = true;
// fall through
case 'U':
if (!typeSet) {
constraintIType = DataDictionary.UNIQUE_CONSTRAINT;
typeSet = true;
}
// fall through
case 'F':
if (!typeSet) constraintIType = DataDictionary.FOREIGNKEY_CONSTRAINT;
if (SanityManager.DEBUG) {
if (!(parentTupleDescriptor instanceof SubKeyConstraintDescriptor)) {
SanityManager.THROWASSERT(
"parentTupleDescriptor expected to be instanceof "
+ "SubKeyConstraintDescriptor, not "
+ parentTupleDescriptor.getClass().getName());
}
}
conglomDesc =
td.getConglomerateDescriptor(
((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId());
/* Take care the rare case of conglomDesc being null. The
* reason is that our "td" is out of date. Another thread
* which was adding a constraint committed between the moment
* we got the table descriptor (conglomerate list) and the
* moment we scanned and got the constraint desc list. Since
* that thread just added a new row to SYSCONGLOMERATES,
* SYSCONSTRAINTS, etc. We wouldn't have wanted to lock the
* system tables just to prevent other threads from adding new
* rows.
*/
if (conglomDesc == null) {
// we can't be getting td from cache because if we are
// here, we must have been in dd's ddl mode (that's why
// the ddl thread went through), we are not done yet, the
// dd ref count is not 0, hence it couldn't have turned
// into COMPILE_ONLY mode
td = dd.getTableDescriptor(tableUUID);
if (scd != null) scd.setTableDescriptor(td);
// try again now
conglomDesc =
td.getConglomerateDescriptor(
((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId());
}
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
conglomDesc != null, "conglomDesc is expected to be non-null for backing index");
}
keyColumns = conglomDesc.getIndexDescriptor().baseColumnPositions();
referencedConstraintId =
((SubKeyConstraintDescriptor) parentTupleDescriptor).getKeyConstraintId();
keyColumns = conglomDesc.getIndexDescriptor().baseColumnPositions();
break;
case 'C':
constraintIType = DataDictionary.CHECK_CONSTRAINT;
if (SanityManager.DEBUG) {
if (!(parentTupleDescriptor instanceof SubCheckConstraintDescriptor)) {
SanityManager.THROWASSERT(
"parentTupleDescriptor expected to be instanceof "
+ "SubCheckConstraintDescriptor, not "
+ parentTupleDescriptor.getClass().getName());
}
}
break;
default:
if (SanityManager.DEBUG) {
SanityManager.THROWASSERT("Fourth column value invalid");
}
}
/* 5th column is SCHEMAID (UUID - char(36)) */
col = row.getColumn(SYSCONSTRAINTS_SCHEMAID);
schemaUUIDString = col.getString();
schemaUUID = getUUIDFactory().recreateUUID(schemaUUIDString);
schema = dd.getSchemaDescriptor(schemaUUID, null);
/* 6th column is STATE (char(1)) */
col = row.getColumn(SYSCONSTRAINTS_STATE);
constraintStateStr = col.getString();
if (SanityManager.DEBUG) {
SanityManager.ASSERT(constraintStateStr.length() == 1, "Sixth column (state) type incorrect");
}
switch (constraintStateStr.charAt(0)) {
case 'E':
constraintEnabled = true;
break;
case 'D':
constraintEnabled = false;
break;
default:
constraintEnabled = true;
if (SanityManager.DEBUG) {
SanityManager.THROWASSERT(
"Invalidate state value '" + constraintStateStr + "' for constraint");
}
}
/* 7th column is REFERENCECOUNT, boolean */
col = row.getColumn(SYSCONSTRAINTS_REFERENCECOUNT);
referenceCount = col.getInt();
/* now build and return the descriptor */
switch (constraintIType) {
case DataDictionary.PRIMARYKEY_CONSTRAINT:
constraintDesc =
ddg.newPrimaryKeyConstraintDescriptor(
td,
constraintName,
false, // deferable,
false, // initiallyDeferred,
keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
constraintUUID,
((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
schema,
constraintEnabled,
referenceCount);
break;
case DataDictionary.UNIQUE_CONSTRAINT:
constraintDesc =
ddg.newUniqueConstraintDescriptor(
td,
constraintName,
false, // deferable,
false, // initiallyDeferred,
keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
constraintUUID,
((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
schema,
constraintEnabled,
referenceCount);
break;
case DataDictionary.FOREIGNKEY_CONSTRAINT:
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
referenceCount == 0, "REFERENCECOUNT column is nonzero for fk constraint");
}
constraintDesc =
ddg.newForeignKeyConstraintDescriptor(
td,
constraintName,
false, // deferable,
false, // initiallyDeferred,
keyColumns, // genReferencedColumns(dd, td), //int referencedColumns[],
constraintUUID,
((SubKeyConstraintDescriptor) parentTupleDescriptor).getIndexId(),
schema,
referencedConstraintId,
constraintEnabled,
((SubKeyConstraintDescriptor) parentTupleDescriptor).getRaDeleteRule(),
((SubKeyConstraintDescriptor) parentTupleDescriptor).getRaUpdateRule());
break;
case DataDictionary.CHECK_CONSTRAINT:
if (SanityManager.DEBUG) {
SanityManager.ASSERT(
referenceCount == 0, "REFERENCECOUNT column is nonzero for check constraint");
}
constraintDesc =
ddg.newCheckConstraintDescriptor(
td,
constraintName,
false, // deferable,
false, // initiallyDeferred,
constraintUUID,
((SubCheckConstraintDescriptor) parentTupleDescriptor).getConstraintText(),
((SubCheckConstraintDescriptor) parentTupleDescriptor)
.getReferencedColumnsDescriptor(),
schema,
constraintEnabled);
break;
}
return constraintDesc;
}
/**
* This is the guts of the Execution-time logic for CREATE TRIGGER.
*
* @see ConstantAction#executeConstantAction
* @exception StandardException Thrown on failure
*/
public void executeConstantAction(Activation activation) throws StandardException {
SPSDescriptor whenspsd = null;
SPSDescriptor actionspsd;
LanguageConnectionContext lcc = activation.getLanguageConnectionContext();
DataDictionary dd = lcc.getDataDictionary();
DependencyManager dm = dd.getDependencyManager();
TransactionController tc = lcc.getTransactionExecute();
/*
** Indicate that we are about to modify the data dictionary.
**
** We tell the data dictionary we're done writing at the end of
** the transaction.
*/
dd.startWriting(lcc);
SchemaDescriptor triggerSd = getSchemaDescriptorForCreate(dd, activation, triggerSchemaName);
if (spsCompSchemaId == null) {
SchemaDescriptor def = lcc.getDefaultSchema();
if (def.getUUID() == null) {
// Descriptor for default schema is stale,
// look it up in the dictionary
def = dd.getSchemaDescriptor(def.getDescriptorName(), tc, false);
}
/*
** It is possible for spsCompSchemaId to be null. For instance,
** the current schema may not have been physically created yet but
** it exists "virtually". In this case, its UUID will have the
** value of null meaning that it is not persistent. e.g.:
**
** CONNECT 'db;create=true' user 'ernie';
** CREATE TABLE bert.t1 (i INT);
** CREATE TRIGGER bert.tr1 AFTER INSERT ON bert.t1
** FOR EACH STATEMENT MODE DB2SQL
** SELECT * FROM SYS.SYSTABLES;
**
** Note that in the above case, the trigger action statement have a
** null compilation schema. A compilation schema with null value
** indicates that the trigger action statement text does not have
** any dependencies with the CURRENT SCHEMA. This means:
**
** o It is safe to compile this statement in any schema since
** there is no dependency with the CURRENT SCHEMA. i.e.: All
** relevent identifiers are qualified with a specific schema.
**
** o The statement cache mechanism can utilize this piece of
** information to enable better statement plan sharing across
** connections in different schemas; thus, avoiding unnecessary
** statement compilation.
*/
if (def != null) spsCompSchemaId = def.getUUID();
}
String tabName;
if (triggerTable != null) {
triggerTableId = triggerTable.getUUID();
tabName = triggerTable.getName();
} else tabName = "with UUID " + triggerTableId;
/* We need to get table descriptor again. We simply can't trust the
* one we got at compile time, the lock on system table was released
* when compile was done, and the table might well have been dropped.
*/
triggerTable = dd.getTableDescriptor(triggerTableId);
if (triggerTable == null) {
throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND_DURING_EXECUTION, tabName);
}
/* Lock the table for DDL. Otherwise during our execution, the table
* might be changed, even dropped. Beetle 4269
*/
lockTableForDDL(tc, triggerTable.getHeapConglomerateId(), true);
/* get triggerTable again for correctness, in case it's changed before
* the lock is aquired
*/
triggerTable = dd.getTableDescriptor(triggerTableId);
if (triggerTable == null) {
throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND_DURING_EXECUTION, tabName);
}
/*
** Send an invalidate on the table from which
** the triggering event emanates. This it
** to make sure that DML statements on this table
** will be recompiled. Do this before we create
** our trigger spses lest we invalidate them just
** after creating them.
*/
dm.invalidateFor(triggerTable, DependencyManager.CREATE_TRIGGER, lcc);
/*
** Lets get our trigger id up front, we'll use it when
** we create our spses.
*/
UUID tmpTriggerId = dd.getUUIDFactory().createUUID();
actionSPSId = (actionSPSId == null) ? dd.getUUIDFactory().createUUID() : actionSPSId;
DataDescriptorGenerator ddg = dd.getDataDescriptorGenerator();
/*
** Create the trigger descriptor first so the trigger action
** compilation can pick up the relevant trigger especially in
** the case of self triggering.
*/
TriggerDescriptor triggerd =
ddg.newTriggerDescriptor(
triggerSd,
tmpTriggerId,
triggerName,
eventMask,
isBefore,
isRow,
isEnabled,
triggerTable,
whenspsd == null ? null : whenspsd.getUUID(),
actionSPSId,
creationTimestamp == null
? new Timestamp(System.currentTimeMillis())
: creationTimestamp,
referencedCols,
originalActionText,
referencingOld,
referencingNew,
oldReferencingName,
newReferencingName);
dd.addDescriptor(triggerd, triggerSd, DataDictionary.SYSTRIGGERS_CATALOG_NUM, false, tc);
/*
** If we have a WHEN action we create it now.
*/
if (whenText != null) {
whenspsd =
createSPS(
lcc,
ddg,
dd,
tc,
tmpTriggerId,
triggerSd,
whenSPSId,
spsCompSchemaId,
whenText,
true,
triggerTable);
}
/*
** Create the trigger action
*/
actionspsd =
createSPS(
lcc,
ddg,
dd,
tc,
tmpTriggerId,
triggerSd,
actionSPSId,
spsCompSchemaId,
actionText,
false,
triggerTable);
/*
** Make underlying spses dependent on the trigger.
*/
if (whenspsd != null) {
dm.addDependency(triggerd, whenspsd, lcc.getContextManager());
}
dm.addDependency(triggerd, actionspsd, lcc.getContextManager());
dm.addDependency(triggerd, triggerTable, lcc.getContextManager());
dm.addDependency(actionspsd, triggerTable, lcc.getContextManager());
// store trigger's dependency on various privileges in the dependeny system
storeViewTriggerDependenciesOnPrivileges(activation, triggerd);
}