diff options
| -rw-r--r-- | doc/src/sgml/hash.sgml | 9 | ||||
| -rw-r--r-- | src/backend/access/hash/README | 9 |
2 files changed, 8 insertions, 10 deletions
diff --git a/doc/src/sgml/hash.sgml b/doc/src/sgml/hash.sgml index 9e69ef91fe8..34f3b2cb0c1 100644 --- a/doc/src/sgml/hash.sgml +++ b/doc/src/sgml/hash.sgml @@ -125,11 +125,10 @@ Both scanning the index and inserting tuples require locating the bucket where a given tuple ought to be located. To do this, we need the bucket count, highmask, and lowmask from the metapage; however, it's undesirable - for performance reasons to have to have to lock and pin the metapage for - every such operation. Instead, we retain a cached copy of the metapage - in each backend's relcache entry. This will produce the correct bucket - mapping as long as the target bucket hasn't been split since the last - cache refresh. + for performance reasons to have to lock and pin the metapage for every such + operation. Instead, we retain a cached copy of the metapage in each + backend's relcache entry. This will produce the correct bucket mapping as + long as the target bucket hasn't been split since the last cache refresh. </para> <para> diff --git a/src/backend/access/hash/README b/src/backend/access/hash/README index 13dc59c124a..fc9031117c9 100644 --- a/src/backend/access/hash/README +++ b/src/backend/access/hash/README @@ -171,11 +171,10 @@ Metapage Caching Both scanning the index and inserting tuples require locating the bucket where a given tuple ought to be located. To do this, we need the bucket count, highmask, and lowmask from the metapage; however, it's undesirable -for performance reasons to have to have to lock and pin the metapage for -every such operation. Instead, we retain a cached copy of the metapage -in each backend's relcache entry. This will produce the correct -bucket mapping as long as the target bucket hasn't been split since the -last cache refresh. +for performance reasons to have to lock and pin the metapage for every such +operation. Instead, we retain a cached copy of the metapage in each backend's +relcache entry. This will produce the correct bucket mapping as long as the +target bucket hasn't been split since the last cache refresh. To guard against the possibility that such a split has occurred, the primary page of each bucket chain stores the number of buckets that |