apache · Alena0704 · Jul 29, 2026
diff --git a/.github/workflows/build-cloudberry-rocky8.yml b/.github/workflows/build-cloudberry-rocky8.yml
@@ -310,6 +310,7 @@ jobs:
                                "contrib/pgcrypto:installcheck",
                                "contrib/pgstattuple:installcheck",
                                "contrib/tablefunc:installcheck",
+                               "contrib/try_convert:installcheck",
                                "contrib/passwordcheck:installcheck",
                                "contrib/pg_buffercache:installcheck",
                                "contrib/sslinfo:installcheck"]

diff --git a/.github/workflows/build-cloudberry.yml b/.github/workflows/build-cloudberry.yml
@@ -308,6 +308,7 @@ jobs:
                                "contrib/pgcrypto:installcheck",
                                "contrib/pgstattuple:installcheck",
                                "contrib/tablefunc:installcheck",
+                               "contrib/try_convert:installcheck",
                                "contrib/passwordcheck:installcheck",
                                "contrib/pg_buffercache:installcheck",
                                "contrib/sslinfo:installcheck"]

diff --git a/.github/workflows/build-deb-cloudberry-ubuntu24.04.yml b/.github/workflows/build-deb-cloudberry-ubuntu24.04.yml
@@ -249,6 +249,7 @@ jobs:
                                "contrib/pgcrypto:installcheck",
                                "contrib/pgstattuple:installcheck",
                                "contrib/tablefunc:installcheck",
+                               "contrib/try_convert:installcheck",
                                "contrib/passwordcheck:installcheck",
                                "contrib/pg_buffercache:installcheck",
                                "contrib/sslinfo:installcheck"]

diff --git a/.github/workflows/build-deb-cloudberry.yml b/.github/workflows/build-deb-cloudberry.yml
@@ -242,6 +242,7 @@ jobs:
                                "contrib/pgcrypto:installcheck",
                                "contrib/pgstattuple:installcheck",
                                "contrib/tablefunc:installcheck",
+                               "contrib/try_convert:installcheck",
                                "contrib/passwordcheck:installcheck",
                                "contrib/pg_buffercache:installcheck",
                                "contrib/sslinfo:installcheck"]

diff --git a/GNUmakefile.in b/GNUmakefile.in
@@ -27,6 +27,7 @@ all:
 	$(MAKE) -C contrib/btree_gin all
 	$(MAKE) -C contrib/pg_trgm all
 	$(MAKE) -C contrib/tablefunc all
+	$(MAKE) -C contrib/try_convert all
 	$(MAKE) -C contrib/passwordcheck all
 	$(MAKE) -C contrib/pg_buffercache all
 ifeq ($(with_openssl), yes)
@@ -77,6 +78,7 @@ install:
 	$(MAKE) -C contrib/btree_gin $@
 	$(MAKE) -C contrib/pg_trgm $@
 	$(MAKE) -C contrib/tablefunc $@
+	$(MAKE) -C contrib/try_convert $@
 	$(MAKE) -C contrib/passwordcheck $@
 	$(MAKE) -C contrib/pg_buffercache $@
 ifeq ($(enable_pax), yes)

diff --git a/contrib/Makefile b/contrib/Makefile
@@ -50,6 +50,7 @@ SUBDIRS = \
 		tablefunc	\
 		tcn		\
 		test_decoding	\
+		try_convert	\
 		tsm_system_rows \
 		tsm_system_time \
 		unaccent	\

diff --git a/contrib/try_convert/.gitignore b/contrib/try_convert/.gitignore
@@ -0,0 +1,6 @@
+# Generated subdirectories
+/results/
+/sql/
+/expected/
+/input/
+/output/
diff --git a/contrib/try_convert/Makefile b/contrib/try_convert/Makefile
@@ -0,0 +1,52 @@
+# contrib/try_convert/Makefile
+
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+MODULE_big	= try_convert
+OBJS		= try_convert.o $(WIN32RES)
+
+EXTENSION = try_convert
+DATA = try_convert--1.0.sql
+PGFILEDESC = "try_convert - function for type cast"
+
+# The test cases are derived from the catalog files and from the sample values
+# in data/, so they are generated by generate-tests rather than stored in the
+# tree, together with the sql/ and expected/ files pg_regress derives from them.
+REGRESS = try_convert
+REGRESS_PREP = generate-tests
+EXTRA_CLEAN = input output sql expected results
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/try_convert
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
+
+.PHONY: generate-tests
+generate-tests:
+	$(MKDIR_P) input output
+	python3 scripts/generate_test.py
+
+.PHONY: verify
+verify: generate-tests
+	python3 scripts/verify.py
diff --git a/contrib/try_convert/README.md b/contrib/try_convert/README.md
@@ -0,0 +1,116 @@
+# TRY_CONVERT
+
+TRY_CONVERT is Greenplum/Cloudberry extension, which adds function for error-safe type cast like [TRY_CAST from SQL-Server](https://learn.microsoft.com/ru-ru/sql/t-sql/functions/try-cast-transact-sql?view=sql-server-ver16)
+
+## Usage
+
+```
+TRY_CONVERT(SOURCE_VALUE, DEFAULT_VALUE::TARGET_TYPE) 
+    returns (VALUE_IN_TARGET_TYPE or DEFAULT_VALUE)
+```
+
+```
+TRY_CONVERT('42'::text, NULL::int2) -- returns 42::int2
+TRY_CONVERT('42d'::text, NULL::int2) -- returns NULL::int2
+TRY_CONVERT('42d'::text, 1234::int2) -- returns 1234::int2
+```
+
+### Extension's type casts
+
+Casting from extensions types is able only for extensions:
+
+- hstore
+- citext
+
+To enable casting from hstore and citext types use, `add_type_for_try_convert(regtype)` function
+
+## Error handling
+
+The cast is executed inside a `PG_TRY()` block: when the cast function reports
+a failure, the error is discarded and the default value is returned instead.
+Query cancellation and assertion failures are never swallowed, they are
+re-thrown, the same way plpgsql handles `EXCEPTION WHEN others`.
+
+The long-term plan is to replace the `PG_TRY()` block by the "soft" error
+handling concept introduced in Postgres 17 (https://github.com/postgres/postgres/commit/ccff2d20ed9622815df2a7deffce8a7b14830965),
+which lets a datatype input function report a conversion failure without
+throwing. That concept was spread on data types in [21be368
+Preview](https://github.com/open-gpdb/gpdb/commit/21be3688729ec4468ffd083da197721860fa2cbd) and [d31f362
+](https://github.com/open-gpdb/gpdb/commit/d31f362250105e456961c2c9249693e42e67eca9) commits.
+It requires converting the datatype input functions of Cloudberry first.
+
+## Why signature is so strange?
+
+Greenplum/Cloudberry function polymorphism accept to have polymorphic functions only one any type in signature.  
+
+## Supported casts
+
+    ✅ Values Cast
+    ✅ Types with typemod
+    ❌ Array-Array Cast
+    ❌ To Domain type cast
+
+An unsupported or non-existing cast is a query error, it is not turned into the
+default value: only failures caused by the converted data are.
+
+## Tests
+
+The regression test is generated out of the catalog files and of the sample
+values in `data/`, so it is not stored in the repository. `make installcheck`
+generates it into `input/` and `output/` and then runs it:
+
+```
+make -C contrib/try_convert installcheck
+```
+
+`make -C contrib/try_convert generate-tests` generates it without running it.
+
+## Benchmark results by pgbench
+
+
+|     | without errors | with errors |
+| --- | --- | --- |
+| cast | 299.346 | ❌ fails |
+| try_convert | 984.280 | 1004.524 |
+| sql | 1384.784 | 5787.115 |
+| sql execute | 5843.220 | 5898.813 |
+
+
+SQL version:
+```
+CREATE OR REPLACE FUNCTION try_convert_into_int(_in text, d int2) RETURNS int2
+  LANGUAGE plpgsql AS
+$func$
+    BEGIN
+        RETURN CAST(_in AS int2);
+        EXCEPTION WHEN others THEN
+        RETURN d;
+    END
+$func$;
+```
+
+
+SQL with execute version:
+```
+CREATE OR REPLACE FUNCTION try_convert_by_sql(_in text, INOUT _out ANYELEMENT)
+  LANGUAGE plpgsql AS
+$func$
+BEGIN
+   EXECUTE format('SELECT %L::%s', $1, pg_typeof(_out))
+   INTO  _out;
+EXCEPTION WHEN others THEN
+   -- do nothing: _out already carries default
+END
+$func$;
+```
+
+Data:
+```
+drop table if exists text_ints; create table text_ints (n text);
+Insert into text_ints(n) select (random()*1000)::int4::text from generate_series(1,1000000);
+
+drop table if exists text_error_ints; create table text_error_ints (n text);
+Insert into text_error_ints(n) select (random()*1000000)::int8::text from generate_series(1,1000000);
+```
+
+
diff --git a/contrib/try_convert/data/corr_date.data b/contrib/try_convert/data/corr_date.data
@@ -0,0 +1,40 @@
+13:35:45
+13:35:90
+13:121:45
+2323:35:45
+13:35:-45
+13:-35:45
+-13:35:45
+
+12:52:43 AM
+15:52:43 AM
+12:152:43 AM
+12:52:143 AM
+12:52:43 PM
+15:52:43 PM
+12:152:43 PM
+12:52:143 PM
+
+21:52:07 JST
+21:52:07 MSSSSSK
+
+21:52:07+03:02
+21:52:07+33:02
+21:52:07-33:02
+21:52:07+03:222
+
+1982-06-27 18:52:43
+1982-06-32 18:52:43
+1982-32-27 18:52:43
+99999999999999-06-27 18:52:43
+
+1982-12-12 01:01:59+09:00
+1982-12-12 01:01:59+29:00
+
+1982-06-27
+1982-06-32
+1982-32-27
+999999999999999-06-27
+
+11-30-0002 BC
+11-30-200000000 BC
diff --git a/contrib/try_convert/data/corr_float4.data b/contrib/try_convert/data/corr_float4.data
@@ -0,0 +1,17 @@
+1
+2
+333333333
+333333333333333333333
+5555555555555555555555555555555555555555555
+dfgdg435fw2342rf445
+6.6332342343243242342342342342343243244324
+354345345345435345345345345.23467567867325345345
+$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7
+Twenty-two
+12234441231.13123123
+485728435843759345135.4324234234
+4823849249230.f
+19203234723472-e102
+0000000000000.00000000000000000001
+234324+e4443
diff --git a/contrib/try_convert/data/corr_float8.data b/contrib/try_convert/data/corr_float8.data
@@ -0,0 +1,17 @@
+1
+2
+333333333
+333333333333333333333
+5555555555555555555555555555555555555555555
+dfgdg435fw2342rf445
+6.6332342343243242342342342342343243244324
+354345345345435345345345345.23467567867325345345
+$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7
+Twenty-two
+12234441231.13123123
+485728435843759345135.4324234234
+4823849249230.f
+19203234723472-e102
+0000000000000.00000000000000000001
+234324+e4443
diff --git a/contrib/try_convert/data/corr_int2.data b/contrib/try_convert/data/corr_int2.data
@@ -0,0 +1,17 @@
+1
+2
+333333333
+333333333333333333333
+5555555555555555555555555555555555555555555
+dfgdg435fw2342rf445
+6.6332342343243242342342342342343243244324
+354345345345435345345345345.23467567867325345345
+$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7
+Twenty-two
+12234441231.13123123
+485728435843759345135.4324234234
+4823849249230.f
+19203234723472-e102
+0000000000000.00000000000000000001
+234324+e4443
diff --git a/contrib/try_convert/data/corr_int4.data b/contrib/try_convert/data/corr_int4.data
@@ -0,0 +1,17 @@
+1
+2
+333333333
+333333333333333333333
+5555555555555555555555555555555555555555555
+dfgdg435fw2342rf445
+6.6332342343243242342342342342343243244324
+354345345345435345345345345.23467567867325345345
+$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7
+Twenty-two
+12234441231.13123123
+485728435843759345135.4324234234
+4823849249230.f
+19203234723472-e102
+0000000000000.00000000000000000001
+234324+e4443
diff --git a/contrib/try_convert/data/corr_int8.data b/contrib/try_convert/data/corr_int8.data
@@ -0,0 +1,17 @@
+1
+2
+333333333
+333333333333333333333
+5555555555555555555555555555555555555555555
+dfgdg435fw2342rf445
+6.6332342343243242342342342342343243244324
+354345345345435345345345345.23467567867325345345
+$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7
+Twenty-two
+12234441231.13123123
+485728435843759345135.4324234234
+4823849249230.f
+19203234723472-e102
+0000000000000.00000000000000000001
+234324+e4443
diff --git a/contrib/try_convert/data/corr_json.data b/contrib/try_convert/data/corr_json.data
@@ -0,0 +1,18 @@
+{
+
+[
+{"world":"CC", "query":"AA", "line":14, "disabled":false, "date":"CAC", "coauthors":"AB"}
+{"world":"CCquery":"AA"}
+{,,,,,,}
+{"world":"CC",,,,, "query":"AA", "line":14, "disabled":false, "date":"CAC", "coauthors":"AB"}
+{"world":"CC", "query"::"AA", "line":14, "disabled":false, "date":"CAC", "coauthors":"AB"}
+
+{"world"}
+{"world":"CC", "query":["AA":"BB", "sds"], "line":14, "disabled":false, "date":"CAC", "coauthors":"AB"}
+}}}}}}}}
+[[[[[[]]]]]]
+{[]}
+[{}]
+][][][][][][]
+{}}{}{}}}{{{}{}{}{}}}}
+kfgbidsfgadgbdfiugbhdiug