reflected review changes for #44

Makefile

@@ -13,8 +13,7 @@ OBJS = cstore.pb-c.o cstore_fdw.o cstore_writer.o cstore_reader.o \
 EXTENSION = cstore_fdw
 DATA = cstore_fdw--1.1.sql cstore_fdw--1.0--1.1.sql
 
-REGRESS = create load query analyze data_types functions block_filtering drop \
-			insert copyto variable_length 
+REGRESS = create load query analyze data_types functions block_filtering drop insert copyto
 EXTRA_CLEAN = cstore.pb-c.h cstore.pb-c.c data/*.cstore data/*.cstore.footer \
               sql/block_filtering.sql sql/create.sql sql/data_types.sql sql/load.sql \
               sql/copyto.sql expected/block_filtering.out expected/create.out \

cstore_writer.c

@@ -238,12 +238,13 @@ CStoreWriteRow(TableWriteState *writeState, Datum *columnValues, bool *columnNul
 			int columnTypeLength = attributeForm->attlen;
 			Oid columnCollation = attributeForm->attcollation;
 			Datum columnValue = columnValues[columnIndex];
-			bool variableLengthColumn = columnTypeLength == -1;
 
-			if (variableLengthColumn)
+			/* detoast variable length attributes if necessary */
+			if (columnTypeLength == -1)
 			{
-				columnValue  = PointerGetDatum(
-						PG_DETOAST_DATUM(columnValues[columnIndex]));
+				struct varlena *detoastedValue = PG_DETOAST_DATUM(columnValue);
+
+				columnValue  = PointerGetDatum(detoastedValue);
 			}
 
 			blockData->existsArray[blockRowIndex] = true;

expected/insert.out

@@ -49,3 +49,40 @@ select count(*) from test_insert_command;
 
 drop table test_insert_command_data;
 drop foreign table test_insert_command;
+-- test long attribute value insertion
+-- create sufficiently long text so that data is stored in toast
+CREATE TABLE test_long_text AS
+SELECT a as int_val, string_agg(random()::text, '') as text_val
+FROM generate_series(1, 10) a, generate_series(1, 1000) b
+GROUP BY a ORDER BY a;
+-- store hash values of text for later comparison
+CREATE TABLE test_long_text_hash AS
+SELECT int_val, md5(text_val) AS hash
+FROM test_long_text;
+CREATE FOREIGN TABLE test_cstore_long_text(int_val int, text_val text)
+SERVER cstore_server;
+-- store long text in cstore table
+INSERT INTO test_cstore_long_text SELECT * FROM test_long_text;
+-- drop source table to remove original text from toast
+DROP TABLE test_long_text;
+-- check if text data is still available in cstore table
+-- by comparing previously stored hash.
+SELECT a.int_val
+FROM  test_long_text_hash a, test_cstore_long_text c
+WHERE a.int_val = c.int_val AND a.hash = md5(c.text_val);
+ int_val 
+---------
+       1
+       2
+       3
+       4
+       5
+       6
+       7
+       8
+       9
+      10
+(10 rows)
+
+DROP TABLE test_long_text_hash;
+DROP FOREIGN TABLE test_cstore_long_text;

sql/insert.sql

@@ -24,3 +24,33 @@ select count(*) from test_insert_command;
 
 drop table test_insert_command_data;
 drop foreign table test_insert_command;
+
+-- test long attribute value insertion
+-- create sufficiently long text so that data is stored in toast
+CREATE TABLE test_long_text AS
+SELECT a as int_val, string_agg(random()::text, '') as text_val
+FROM generate_series(1, 10) a, generate_series(1, 1000) b
+GROUP BY a ORDER BY a;
+
+-- store hash values of text for later comparison
+CREATE TABLE test_long_text_hash AS
+SELECT int_val, md5(text_val) AS hash
+FROM test_long_text;
+
+CREATE FOREIGN TABLE test_cstore_long_text(int_val int, text_val text)
+SERVER cstore_server;
+
+-- store long text in cstore table
+INSERT INTO test_cstore_long_text SELECT * FROM test_long_text;
+
+-- drop source table to remove original text from toast
+DROP TABLE test_long_text;
+
+-- check if text data is still available in cstore table
+-- by comparing previously stored hash.
+SELECT a.int_val
+FROM  test_long_text_hash a, test_cstore_long_text c
+WHERE a.int_val = c.int_val AND a.hash = md5(c.text_val);
+
+DROP TABLE test_long_text_hash;
+DROP FOREIGN TABLE test_cstore_long_text;