Support text position search functions with nondeterministic collations This allows using text position search functions with nondeterministic collations. These functions are
- position, strpos - replace - split_part - string_to_array - string_to_table which all use common internal infrastructure. There was previously no internal implementation of this, so it was met with a not-supported error. This adds the internal implementation and removes the error. Unlike with deterministic collations, the search cannot use any byte-by-byte optimized techniques but has to go substring by substring. We also need to consider that the found match could have a different length than the needle and that there could be substrings of different length matching at a position. In most cases, we need to find the longest such substring (greedy semantics), but this can be configured by each caller. Reviewed-by: Euler Taveira <eu...@eulerto.com> Discussion: https://www.postgresql.org/message-id/flat/582b2613-0900-48ca-8b0d-340c06f4d...@eisentraut.org Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/329304c9012b2ac6d906afeb18062f9080dceef9 Modified Files -------------- src/backend/utils/adt/varlena.c | 104 ++++++++++++++--- src/test/regress/expected/collate.icu.utf8.out | 154 ++++++++++++++++++++----- src/test/regress/sql/collate.icu.utf8.sql | 36 +++++- 3 files changed, 246 insertions(+), 48 deletions(-)
