diff options
Diffstat (limited to 'src/backend/tcop/pquery.c')
| -rw-r--r-- | src/backend/tcop/pquery.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c index 466727b7b8..75c7dee3cb 100644 --- a/src/backend/tcop/pquery.c +++ b/src/backend/tcop/pquery.c @@ -446,16 +446,17 @@ FetchStatementTargetList(Node *stmt) * the query, they must be passed in here (caller is responsible for * giving them appropriate lifetime). * - * The caller can optionally pass a snapshot to be used; pass InvalidSnapshot - * for the normal behavior of setting a new snapshot. This parameter is - * presently ignored for non-PORTAL_ONE_SELECT portals (it's only intended - * to be used for cursors). + * The use_active_snapshot parameter is currently used only for + * PORTAL_ONE_SELECT portals. If it is true, the active snapshot will + * be used when starting up the executor; if false, a new snapshot will + * be taken. This is used both for cursors and to avoid taking an entirely + * new snapshot when it isn't necessary. * * On return, portal is ready to accept PortalRun() calls, and the result * tupdesc (if any) is known. */ void -PortalStart(Portal portal, ParamListInfo params, Snapshot snapshot) +PortalStart(Portal portal, ParamListInfo params, bool use_active_snapshot) { Portal saveActivePortal; ResourceOwner saveResourceOwner; @@ -497,8 +498,8 @@ PortalStart(Portal portal, ParamListInfo params, Snapshot snapshot) case PORTAL_ONE_SELECT: /* Must set snapshot before starting executor. */ - if (snapshot) - PushActiveSnapshot(snapshot); + if (use_active_snapshot) + PushActiveSnapshot(GetActiveSnapshot()); else PushActiveSnapshot(GetTransactionSnapshot()); |