diff options
Diffstat (limited to 'src/include/utils/portal.h')
| -rw-r--r-- | src/include/utils/portal.h | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h index c9ca8547ce2..0201b0684c3 100644 --- a/src/include/utils/portal.h +++ b/src/include/utils/portal.h @@ -9,7 +9,7 @@ * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: portal.h,v 1.39 2003/03/11 19:40:24 tgl Exp $ + * $Id: portal.h,v 1.40 2003/03/27 16:51:29 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -18,17 +18,45 @@ #include "executor/execdesc.h" #include "nodes/memnodes.h" +#include "utils/tuplestore.h" +/* + * We support three kinds of scroll behavior: + * + * (1) Neither NO SCROLL nor SCROLL was specified: to remain backward + * compatible, we allow backward fetches here, unless it would + * impose additional runtime overhead to do so. + * + * (2) NO SCROLL was specified: don't allow any backward fetches. + * + * (3) SCROLL was specified: allow all kinds of backward fetches, even + * if we need to take a slight performance hit to do so. + * + * Case #1 is converted to #2 or #3 by looking at the query itself and + * determining if scrollability can be supported without additional + * overhead. + */ +typedef enum +{ + DEFAULT_SCROLL, + DISABLE_SCROLL, + ENABLE_SCROLL +} ScrollType; typedef struct PortalData *Portal; typedef struct PortalData { char *name; /* Portal's name */ - MemoryContext heap; /* subsidiary memory */ + MemoryContext heap; /* memory for storing short-term data */ QueryDesc *queryDesc; /* Info about query associated with portal */ void (*cleanup) (Portal); /* Cleanup routine (optional) */ - bool backwardOK; /* is fetch backwards allowed? */ + ScrollType scrollType; /* Allow backward fetches? */ + bool holdOpen; /* hold open after txn ends? */ + TransactionId createXact; /* the xid of the creating txn */ + Tuplestorestate *holdStore; /* store for holdable cursors */ + MemoryContext holdContext; /* memory for long-term data */ + /* * atStart, atEnd and portalPos indicate the current cursor position. * portalPos is zero before the first row, N after fetching N'th row of @@ -58,11 +86,12 @@ typedef struct PortalData extern void EnablePortalManager(void); -extern void AtEOXact_portals(void); +extern void AtEOXact_portals(bool isCommit); extern Portal CreatePortal(const char *name); -extern void PortalDrop(Portal portal); +extern void PortalDrop(Portal portal, bool persistHoldable); extern Portal GetPortalByName(const char *name); extern void PortalSetQuery(Portal portal, QueryDesc *queryDesc, void (*cleanup) (Portal portal)); +extern void PersistHoldablePortal(Portal portal); #endif /* PORTAL_H */ |