diff options
Diffstat (limited to 'src/include/executor/tuptable.h')
| -rw-r--r-- | src/include/executor/tuptable.h | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/src/include/executor/tuptable.h b/src/include/executor/tuptable.h index 47018666a78..7def0be4b69 100644 --- a/src/include/executor/tuptable.h +++ b/src/include/executor/tuptable.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: tuptable.h,v 1.17 2001/01/24 19:43:23 momjian Exp $ + * $Id: tuptable.h,v 1.18 2001/01/29 00:39:20 tgl Exp $ * * NOTES * The tuple table interface is getting pretty ugly. @@ -22,27 +22,36 @@ /* ---------------- * The executor tuple table is managed and manipulated by special - * code in executor/execTuples.c and tupTable.h + * code in executor/execTuples.c. * * TupleTableSlot information * - * shouldFree boolean - should we call pfree() on tuple + * val current tuple, or NULL if no tuple + * shouldFree boolean - should we pfree() tuple * descIsNew boolean - true when tupleDescriptor changes - * tupleDescriptor type information kept regarding the tuple data + * tupleDescriptor type information for the tuple data + * shouldFreeDesc boolean - should we free tupleDescriptor * buffer the buffer for tuples pointing to disk pages * * The executor stores pointers to tuples in a ``tuple table'' - * which is composed of TupleTableSlot's. Some of the tuples - * are pointers to buffer pages and others are pointers to - * palloc'ed memory and the shouldFree variable tells us when + * which is composed of TupleTableSlots. Sometimes the tuples + * are pointers to buffer pages, while others are pointers to + * palloc'ed memory; the shouldFree variable tells us when * we may call pfree() on a tuple. -cim 9/23/90 * + * If buffer is not InvalidBuffer, then the slot is holding a pin + * on the indicated buffer page; drop the pin when we release the + * slot's reference to that buffer. + * * In the implementation of nested-dot queries such as * "retrieve (EMP.hobbies.all)", a single scan may return tuples * of many types, so now we return pointers to tuple descriptors * along with tuples returned via the tuple table. -cim 1/18/90 * - * Tuple table macros are all excised from the system now. + * shouldFreeDesc is similar to shouldFree: if it's true, then the + * tupleDescriptor is "owned" by the TupleTableSlot and should be + * freed when the slot's reference to the descriptor is dropped. + * * See executor.h for decls of functions defined in execTuples.c * -jolly * @@ -54,6 +63,7 @@ typedef struct TupleTableSlot HeapTuple val; bool ttc_shouldFree; bool ttc_descIsNew; + bool ttc_shouldFreeDesc; TupleDesc ttc_tupleDescriptor; Buffer ttc_buffer; } TupleTableSlot; |