Re: [PATCH] Use Boyer-Moore-Horspool for simple LIKE contains patterns

[Greg Sabino Mullane]

Glad to see all the refinement happening with this patch. Some less
important things:

> * Portions Copyright (c) 1996-2026

This looks like new code. Unless you were working on this in 1996, the
copyrights for the new files (like_bmh.c and like_bmh.h) should be

# Copyright (c) 2026, PostgreSQL Global Development Group

See e.g. src/backend/commands/repack_worker.c


+       if ((pg_database_encoding_max_length() > 1 &&
+                GetDatabaseEncoding() != PG_UTF8) ||
+               !OidIsValid(collation) ||
+               !like_bmh_pattern_is_eligible(p, plen, &literal_len))
+       {
+               state = MemoryContextAlloc(flinfo->fn_mcxt,
sizeof(LikeBMHState));
+               state->mode = LIKE_BMH_GENERIC;
+               flinfo->fn_extra = state;
+               return state;
+       }
+
+       locale = pg_newlocale_from_collation(collation);
+       if (!locale->deterministic)
+       {
+               state = MemoryContextAlloc(flinfo->fn_mcxt,
sizeof(LikeBMHState));
+               state->mode = LIKE_BMH_GENERIC;
+               flinfo->fn_extra = state;
+               return state;
+       }

locale is only used in this one place, so we can remove that var and avoid
writing that same code block twice by rolling the deterministic locale
check directly into the first set of checks:

if ((pg_database_encoding_max_length() > 1 &&
         GetDatabaseEncoding() != PG_UTF8) ||
        !OidIsValid(collation) ||
        !like_bmh_pattern_is_eligible(p, plen, &literal_len) ||
        !pg_newlocale_from_collation(collation)->deterministic)

Cheers,
Greg