CHANGELOG, docs

Author: serprex

CHANGELOG.md

@@ -36,6 +36,8 @@ All notable changes to this project will be documented in this file. It uses the
     `&&` (`hasAny`).
 *   Array slice syntax (`arr[L:U]`, `arr[:U]`, `arr[L:]`) now pushes down
     as `arraySlice()`.
+*   Added pushdown for [pg_re2] extension functions to their ClickHouse
+    equivalents (e.g., `re2match` → `match`, `re2extractall` → `extractAll`).
 
 ### ⬆️ Dependency Updates
 
@@ -52,6 +54,8 @@ All notable changes to this project will be documented in this file. It uses the
     `string_to_array(3-arg)` now evaluate locally instead of being pushed to
     ClickHouse where they would fail.
 
+  [pg_re2]: https://github.com/ClickHouse/pg_re2
+    "pg_re2: ClickHouse-compatible regex functions using RE2"
   [v0.1.11]: https://github.com/ClickHouse/pg_clickhouse/compare/v0.1.10...v0.1.11
 
 ## [v0.1.10] — 2026-04-06

doc/pg_clickhouse.md

@@ -1088,6 +1088,32 @@ any of these functions cannot be pushed down they will raise an exception.
 
 *   [dictGet](https://clickhouse.com/docs/sql-reference/functions/ext-dict-functions#dictget-dictgetordefault-dictgetornull)
 
+### Extension Pushdown
+
+pg_clickhouse recognizes functions from select third-party extensions and
+pushes them down to their ClickHouse equivalents.
+
+#### [pg_re2]
+
+All [pg_re2] functions push down 1:1 to ClickHouse:
+
+*   `re2match` → [match](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#match)
+*   `re2extract` → [extract](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#extract)
+*   `re2extractall` → [extractAll](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#extractAll)
+*   `re2regexpextract` → [regexpExtract](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#regexpExtract)
+*   `re2extractgroups` → [extractGroups](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#extractGroups)
+*   `re2replaceregexpone` → [replaceRegexpOne](https://clickhouse.com/docs/sql-reference/functions/string-replace-functions#replaceRegexpOne)
+*   `re2replaceregexpall` → [replaceRegexpAll](https://clickhouse.com/docs/sql-reference/functions/string-replace-functions#replaceRegexpAll)
+*   `re2countmatches` → [countMatches](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#countMatches)
+*   `re2countmatchescaseinsensitive` → [countMatchesCaseInsensitive](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#countMatchesCaseInsensitive)
+*   `re2multimatchany` → [multiMatchAny](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#multiMatchAny)
+*   `re2multimatchanyindex` → [multiMatchAnyIndex](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#multiMatchAnyIndex)
+*   `re2multimatchallindices` → [multiMatchAllIndices](https://clickhouse.com/docs/sql-reference/functions/string-search-functions#multiMatchAllIndices)
+
+#### [intarray]
+
+*   `idx` → [indexOf](https://clickhouse.com/docs/sql-reference/functions/array-functions#indexOf)
+
 ### Pushdown Casts
 
 pg_clickhouse pushes down casts such as `CAST(x AS bigint)` for compatible
@@ -1323,3 +1349,7 @@ Copyright (c) 2025-2026, ClickHouse.
   [Postgres flags]: https://www.postgresql.org/docs/18/functions-matching.html#POSIX-EMBEDDED-OPTIONS-TABLE
     "PostgreSQL Docs: ARE Embedded-Option Letters"
   [RE2 Regular Expressions]: https://github.com/google/re2/wiki/Syntax "RE2 Syntax"
+  [pg_re2]: https://github.com/ClickHouse/pg_re2
+    "pg_re2: ClickHouse-compatible regex functions using RE2"
+  [intarray]: https://www.postgresql.org/docs/current/intarray.html
+    "PostgreSQL Docs: intarray"