contrast, a hash index allows accessing the bucket pages directly,
thereby potentially reducing index access time in larger tables. This
reduction in "logical I/O" becomes even more pronounced on indexes/data
- larger than shared_buffers/RAM.
+ larger than shared_buffers/RAM.
overflow page becomes empty, overflow pages can be recycled for reuse
in other buckets, though we never return them to the operating system.
There is currently no provision to shrink a hash index, other than by
- rebuilding it with REINDEX.
+ rebuilding it with REINDEX.
There is no provision for reducing the number of buckets, either.
When verifying checksums, every file in the cluster is scanned. When
- enabling checksums, each relation file block with a changed checksum is
+ enabling checksums, each relation file block with a changed checksum is
rewritten in-place.
Disabling checksums only updates the file pg_control.