diff options
| -rw-r--r-- | src/backend/commands/portalcmds.c | 10 | ||||
| -rw-r--r-- | src/backend/executor/tstoreReceiver.c | 137 | ||||
| -rw-r--r-- | src/backend/tcop/pquery.c | 5 | ||||
| -rw-r--r-- | src/include/executor/tstoreReceiver.h | 5 |
4 files changed, 140 insertions, 17 deletions
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c index 45776277d88..9b74f1bdc1a 100644 --- a/src/backend/commands/portalcmds.c +++ b/src/backend/commands/portalcmds.c @@ -14,7 +14,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.76 2008/11/30 20:51:25 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.77 2008/12/01 17:06:21 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -351,11 +351,15 @@ PersistHoldablePortal(Portal portal) */ ExecutorRewind(queryDesc); - /* Change the destination to output to the tuplestore */ + /* + * Change the destination to output to the tuplestore. Note we + * tell the tuplestore receiver to detoast all data passed through it. + */ queryDesc->dest = CreateDestReceiver(DestTuplestore); SetTuplestoreDestReceiverParams(queryDesc->dest, portal->holdStore, - portal->holdContext); + portal->holdContext, + true); /* Fetch the result set into the tuplestore */ ExecutorRun(queryDesc, ForwardScanDirection, 0L); diff --git a/src/backend/executor/tstoreReceiver.c b/src/backend/executor/tstoreReceiver.c index cb78c80b919..9993f856ffa 100644 --- a/src/backend/executor/tstoreReceiver.c +++ b/src/backend/executor/tstoreReceiver.c @@ -1,46 +1,97 @@ /*------------------------------------------------------------------------- * * tstoreReceiver.c - * an implementation of DestReceiver that stores the result tuples in - * a Tuplestore + * An implementation of DestReceiver that stores the result tuples in + * a Tuplestore. + * + * Optionally, we can force detoasting (but not decompression) of out-of-line + * toasted values. This is to support cursors WITH HOLD, which must retain + * data even if the underlying table is dropped. * * * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/tstoreReceiver.c,v 1.20 2008/11/30 20:51:25 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/executor/tstoreReceiver.c,v 1.21 2008/12/01 17:06:21 tgl Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" +#include "access/tuptoaster.h" #include "executor/tstoreReceiver.h" typedef struct { DestReceiver pub; - Tuplestorestate *tstore; - MemoryContext cxt; + /* parameters: */ + Tuplestorestate *tstore; /* where to put the data */ + MemoryContext cxt; /* context containing tstore */ + bool detoast; /* were we told to detoast? */ + /* workspace: */ + Datum *outvalues; /* values array for result tuple */ + Datum *tofree; /* temp values to be pfree'd */ } TStoreState; +static void tstoreReceiveSlot_notoast(TupleTableSlot *slot, DestReceiver *self); +static void tstoreReceiveSlot_detoast(TupleTableSlot *slot, DestReceiver *self); + + /* * Prepare to receive tuples from executor. */ static void tstoreStartupReceiver(DestReceiver *self, int operation, TupleDesc typeinfo) { - /* do nothing */ + TStoreState *myState = (TStoreState *) self; + bool needtoast = false; + Form_pg_attribute *attrs = typeinfo->attrs; + int natts = typeinfo->natts; + int i; + + /* Check if any columns require detoast work */ + if (myState->detoast) + { + for (i = 0; i < natts; i++) + { + if (attrs[i]->attisdropped) + continue; + if (attrs[i]->attlen == -1) + { + needtoast = true; + break; + } + } + } + + /* Set up appropriate callback */ + if (needtoast) + { + myState->pub.receiveSlot = tstoreReceiveSlot_detoast; + /* Create workspace */ + myState->outvalues = (Datum *) + MemoryContextAlloc(myState->cxt, natts * sizeof(Datum)); + myState->tofree = (Datum *) + MemoryContextAlloc(myState->cxt, natts * sizeof(Datum)); + } + else + { + myState->pub.receiveSlot = tstoreReceiveSlot_notoast; + myState->outvalues = NULL; + myState->tofree = NULL; + } } /* * Receive a tuple from the executor and store it in the tuplestore. + * This is for the easy case where we don't have to detoast. */ static void -tstoreReceiveSlot(TupleTableSlot *slot, DestReceiver *self) +tstoreReceiveSlot_notoast(TupleTableSlot *slot, DestReceiver *self) { TStoreState *myState = (TStoreState *) self; MemoryContext oldcxt = MemoryContextSwitchTo(myState->cxt); @@ -51,12 +102,76 @@ tstoreReceiveSlot(TupleTableSlot *slot, DestReceiver *self) } /* + * Receive a tuple from the executor and store it in the tuplestore. + * This is for the case where we have to detoast any toasted values. + */ +static void +tstoreReceiveSlot_detoast(TupleTableSlot *slot, DestReceiver *self) +{ + TStoreState *myState = (TStoreState *) self; + TupleDesc typeinfo = slot->tts_tupleDescriptor; + Form_pg_attribute *attrs = typeinfo->attrs; + int natts = typeinfo->natts; + int nfree; + int i; + MemoryContext oldcxt; + + /* Make sure the tuple is fully deconstructed */ + slot_getallattrs(slot); + + /* + * Fetch back any out-of-line datums. We build the new datums array in + * myState->outvalues[] (but we can re-use the slot's isnull array). + * Also, remember the fetched values to free afterwards. + */ + nfree = 0; + for (i = 0; i < natts; i++) + { + Datum val = slot->tts_values[i]; + + if (!attrs[i]->attisdropped && + attrs[i]->attlen == -1 && + !slot->tts_isnull[i]) + { + if (VARATT_IS_EXTERNAL(DatumGetPointer(val))) + { + val = PointerGetDatum(heap_tuple_fetch_attr((struct varlena *) + DatumGetPointer(val))); + myState->tofree[nfree++] = val; + } + } + + myState->outvalues[i] = val; + } + + /* + * Push the modified tuple into the tuplestore. + */ + oldcxt = MemoryContextSwitchTo(myState->cxt); + tuplestore_putvalues(myState->tstore, typeinfo, + myState->outvalues, slot->tts_isnull); + MemoryContextSwitchTo(oldcxt); + + /* And release any temporary detoasted values */ + for (i = 0; i < nfree; i++) + pfree(DatumGetPointer(myState->tofree[i])); +} + +/* * Clean up at end of an executor run */ static void tstoreShutdownReceiver(DestReceiver *self) { - /* do nothing */ + TStoreState *myState = (TStoreState *) self; + + /* Release workspace if any */ + if (myState->outvalues) + pfree(myState->outvalues); + myState->outvalues = NULL; + if (myState->tofree) + pfree(myState->tofree); + myState->tofree = NULL; } /* @@ -76,7 +191,7 @@ CreateTuplestoreDestReceiver(void) { TStoreState *self = (TStoreState *) palloc0(sizeof(TStoreState)); - self->pub.receiveSlot = tstoreReceiveSlot; + self->pub.receiveSlot = tstoreReceiveSlot_notoast; /* might change */ self->pub.rStartup = tstoreStartupReceiver; self->pub.rShutdown = tstoreShutdownReceiver; self->pub.rDestroy = tstoreDestroyReceiver; @@ -93,11 +208,13 @@ CreateTuplestoreDestReceiver(void) void SetTuplestoreDestReceiverParams(DestReceiver *self, Tuplestorestate *tStore, - MemoryContext tContext) + MemoryContext tContext, + bool detoast) { TStoreState *myState = (TStoreState *) self; Assert(myState->pub.mydest == DestTuplestore); myState->tstore = tStore; myState->cxt = tContext; + myState->detoast = detoast; } diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c index 2a9764ac8b1..c2a161b0f7f 100644 --- a/src/backend/tcop/pquery.c +++ b/src/backend/tcop/pquery.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.126 2008/11/30 20:51:25 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/tcop/pquery.c,v 1.127 2008/12/01 17:06:21 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1036,7 +1036,8 @@ FillPortalStore(Portal portal, bool isTopLevel) treceiver = CreateDestReceiver(DestTuplestore); SetTuplestoreDestReceiverParams(treceiver, portal->holdStore, - portal->holdContext); + portal->holdContext, + false); completionTag[0] = '\0'; diff --git a/src/include/executor/tstoreReceiver.h b/src/include/executor/tstoreReceiver.h index c304c1fce90..b2d3890f46a 100644 --- a/src/include/executor/tstoreReceiver.h +++ b/src/include/executor/tstoreReceiver.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/executor/tstoreReceiver.h,v 1.11 2008/11/30 20:51:25 tgl Exp $ + * $PostgreSQL: pgsql/src/include/executor/tstoreReceiver.h,v 1.12 2008/12/01 17:06:21 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -23,6 +23,7 @@ extern DestReceiver *CreateTuplestoreDestReceiver(void); extern void SetTuplestoreDestReceiverParams(DestReceiver *self, Tuplestorestate *tStore, - MemoryContext tContext); + MemoryContext tContext, + bool detoast); #endif /* TSTORE_RECEIVER_H */ |