Fix interaction of TOAST compression with expression indexes.

Before, trying to compress a value for insertion into an expression
index would crash.

Dilip Kumar, with some editing by me. Report by Jaime Casanova.

Discussion: http://postgr.es/m/CAJKUy5gcs0zGOp6JXU2mMVdthYhuQpFk=S3V8DOKT=LZC1L36Q@mail.gmail.com

3 files changed, 26 insertions, 0 deletions

diff --git a/src/test/regress/expected/compression.out b/src/test/regress/expected/compression.out
index 566a1877eac..61e97cb33ce 100644
--- a/src/test/regress/expected/compression.out
+++ b/src/test/regress/expected/compression.out
@@ -313,6 +313,12 @@ SELECT pg_column_compression(f1) FROM cmdata;
  lz4
 (2 rows)
 
+-- test expression index
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
+CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
+INSERT INTO cmdata2 VALUES((SELECT array_agg(md5(g::TEXT))::TEXT FROM
+generate_series(1, 50) g), VERSION());
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
diff --git a/src/test/regress/expected/compression_1.out b/src/test/regress/expected/compression_1.out
index 39909334154..d03d6255ae3 100644
--- a/src/test/regress/expected/compression_1.out
+++ b/src/test/regress/expected/compression_1.out
@@ -309,6 +309,19 @@ SELECT pg_column_compression(f1) FROM cmdata;
  pglz
 (2 rows)
 
+-- test expression index
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
+ERROR:  unsupported LZ4 compression method
+DETAIL:  This functionality requires the server to be built with lz4 support.
+HINT:  You need to rebuild PostgreSQL using --with-lz4.
+CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
+ERROR:  relation "cmdata2" does not exist
+INSERT INTO cmdata2 VALUES((SELECT array_agg(md5(g::TEXT))::TEXT FROM
+generate_series(1, 50) g), VERSION());
+ERROR:  relation "cmdata2" does not exist
+LINE 1: INSERT INTO cmdata2 VALUES((SELECT array_agg(md5(g::TEXT))::...
+                    ^
 -- check data is ok
 SELECT length(f1) FROM cmdata;
  length 
diff --git a/src/test/regress/sql/compression.sql b/src/test/regress/sql/compression.sql
index 5e178be04a2..76d1776d832 100644
--- a/src/test/regress/sql/compression.sql
+++ b/src/test/regress/sql/compression.sql
@@ -130,6 +130,13 @@ SELECT pg_column_compression(f1) FROM cmdata;
 VACUUM FULL cmdata;
 SELECT pg_column_compression(f1) FROM cmdata;
 
+-- test expression index
+DROP TABLE cmdata2;
+CREATE TABLE cmdata2 (f1 TEXT COMPRESSION pglz, f2 TEXT COMPRESSION lz4);
+CREATE UNIQUE INDEX idx1 ON cmdata2 ((f1 || f2));
+INSERT INTO cmdata2 VALUES((SELECT array_agg(md5(g::TEXT))::TEXT FROM
+generate_series(1, 50) g), VERSION());
+
 -- check data is ok
 SELECT length(f1) FROM cmdata;
 SELECT length(f1) FROM cmdata1;