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| author | Robert Haas <rhaas@postgresql.org> | 2015-11-11 08:57:52 -0500 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2015-11-11 08:57:52 -0500 |
| commit | f0661c4e8c44c0ec7acd4ea7c82e85b265447398 (patch) | |
| tree | 0a31416ab40a9be4ab0f43c6ddd73221eed9dec6 /src/backend/executor/execAmi.c | |
| parent | f764ecd81b2a8a1e9000d43a73ca5eec8e8008bc (diff) | |
| download | postgresql-f0661c4e8c44c0ec7acd4ea7c82e85b265447398.tar.gz postgresql-f0661c4e8c44c0ec7acd4ea7c82e85b265447398.zip | |
Make sequential scans parallel-aware.
In addition, this path fills in a number of missing bits and pieces in
the parallel infrastructure. Paths and plans now have a parallel_aware
flag indicating whether whatever parallel-aware logic they have should
be engaged. It is believed that we will need this flag for a number of
path/plan types, not just sequential scans, which is why the flag is
generic rather than part of the SeqScan structures specifically.
Also, execParallel.c now gives parallel nodes a chance to initialize
their PlanState nodes from the DSM during parallel worker startup.
Amit Kapila, with a fair amount of adjustment by me. Review of previous
patch versions by Haribabu Kommi and others.
Diffstat (limited to 'src/backend/executor/execAmi.c')
| -rw-r--r-- | src/backend/executor/execAmi.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/backend/executor/execAmi.c b/src/backend/executor/execAmi.c index 163650cecd1..b969fc08037 100644 --- a/src/backend/executor/execAmi.c +++ b/src/backend/executor/execAmi.c @@ -439,6 +439,15 @@ ExecSupportsBackwardScan(Plan *node) if (node == NULL) return false; + /* + * Parallel-aware nodes return a subset of the tuples in each worker, + * and in general we can't expect to have enough bookkeeping state to + * know which ones we returned in this worker as opposed to some other + * worker. + */ + if (node->parallel_aware) + return false; + switch (nodeTag(node)) { case T_Result: |