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| author | Simon Riggs <simon@2ndQuadrant.com> | 2017-03-06 16:04:31 +0530 |
|---|---|---|
| committer | Simon Riggs <simon@2ndQuadrant.com> | 2017-03-06 16:04:31 +0530 |
| commit | 21d4e2e20656381b4652eb675af4f6d65053607f (patch) | |
| tree | 5966f82b9cddeaacd8214ec824f90de13689a821 /src/backend/utils/cache | |
| parent | 8b4d582d279d784616c228be58af1e39aa430402 (diff) | |
| download | postgresql-21d4e2e20656381b4652eb675af4f6d65053607f.tar.gz postgresql-21d4e2e20656381b4652eb675af4f6d65053607f.zip | |
Reduce lock levels for table storage params related to planning
The following parameters are now updateable with ShareUpdateExclusiveLock
effective_io_concurrency
parallel_workers
seq_page_cost
random_page_cost
n_distinct
n_distinct_inherited
Simon Riggs and FabrÃzio Mello
Diffstat (limited to 'src/backend/utils/cache')
| -rw-r--r-- | src/backend/utils/cache/spccache.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/backend/utils/cache/spccache.c b/src/backend/utils/cache/spccache.c index 9dcb80cde0d..eafc00f9ea0 100644 --- a/src/backend/utils/cache/spccache.c +++ b/src/backend/utils/cache/spccache.c @@ -173,6 +173,10 @@ get_tablespace(Oid spcid) /* * get_tablespace_page_costs * Return random and/or sequential page costs for a given tablespace. + * + * This value is not locked by the transaction, so this value may + * be changed while a SELECT that has used these values for planning + * is still executing. */ void get_tablespace_page_costs(Oid spcid, @@ -200,6 +204,13 @@ get_tablespace_page_costs(Oid spcid, } } +/* + * get_tablespace_io_concurrency + * + * This value is not locked by the transaction, so this value may + * be changed while a SELECT that has used these values for planning + * is still executing. + */ int get_tablespace_io_concurrency(Oid spcid) { |