Repeating the query to improve the self-containment aspect of the email would have been appreciated.if possible please have a look on the explain analyze results:What else can I do?The indexes I created is:- CREATE INDEX CONCURRENTLY ix_inode_segments_notes_clientids2 ON gorfs.inode_segments USING btree ("full_path");the only condition that could even potentially use this index is:s.full_path ~ '/userfiles/account/[0-9]+/[a-z]+/[0-9]+'My knowledge is limited in this area, and the documentation covers this specific dynamic only minimally, but for certain attempting to perform an un-anchored regexp match using a btree index is impossible.These leaves to avenues to explore.1) See if a start-of-string anchor will make the btree index usable2) Use the pg_trgm contrib module- CREATE INDEX CONCURRENTLY ix_inodes_checksum_st_size ON gorfs.inodes USING btree ("checksum_md5","st_size");This one was used.IMO you are leaving too much infomation encoded in the full_path. I'd personally setup triggers to parse out the components on insert/update into fields and then index those fields. In fact I'd probably use some form of inheritance or other one-to-one relationship here.
I guess it is documented, I just needed to look a bit more.
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The optimizer can also use a B-tree index for queries involving the pattern matching operators LIKE and ~ if the pattern is a constant and is anchored to the beginning of the string — for example, col LIKE 'foo%' or col ~ '^foo', but not col LIKE '%bar'. However, if your database does not use the C locale you will need to create the index with a special operator class to support indexing of pattern-matching queries; see Section 11.9 below. It is also possible to use B-tree indexes for ILIKE and ~*, but only if the pattern starts with non-alphabetic characters, i.e., characters that are not affected by upper/lower case conversion.
