Use less memory when growing HEAP tables. See MDEV-436

mysql-test/suite/heap/heap.result:
  Added test case for MDEV-436
mysql-test/suite/heap/heap.test:
  Added test case for MDEV-436
storage/heap/hp_block.c:
  Don't allocate a set of HP_PTRS when not needed. This saves us about 1024 bytes for most allocations.
storage/heap/hp_create.c:
  Made the initial allocation of block sizes depending on min_records and max_records.

2 files changed, 47 insertions, 0 deletions

diff --git a/mysql-test/suite/heap/heap.result b/mysql-test/suite/heap/heap.result
index f058c9f9c72..29ebf504e1a 100644
--- a/mysql-test/suite/heap/heap.result
+++ b/mysql-test/suite/heap/heap.result
@@ -738,3 +738,27 @@ SELECT c2 FROM t1;
 c2
 0
 DROP TABLE t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=10 max_rows=100;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+data_length	index_length
+1600	2400
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=10 max_rows=10000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+data_length	index_length
+16000	24000
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=3000 max_rows=3000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+data_length	index_length
+48000	72000
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap max_rows=4000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+data_length	index_length
+16000	24000
+drop table t1;
diff --git a/mysql-test/suite/heap/heap.test b/mysql-test/suite/heap/heap.test
index 7d56425799a..062b48f2c31 100644
--- a/mysql-test/suite/heap/heap.test
+++ b/mysql-test/suite/heap/heap.test
@@ -485,3 +485,26 @@ INSERT INTO t1 VALUES('', 0);
 ALTER TABLE t1 MODIFY c1 VARCHAR(101);
 SELECT c2 FROM t1;
 DROP TABLE t1;
+
+#
+# Show that MIN_ROWS and MAX_ROWS have an effect on how data_length
+# and index_length are allocated.
+# This is different for 32 and 64 bit machines as pointer lengths are different
+#
+
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=10 max_rows=100;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=10 max_rows=10000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap min_rows=3000 max_rows=3000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+drop table t1;
+CREATE TABLE t1 (a int, index(a)) engine=heap max_rows=4000;
+insert into t1 values(1);
+select data_length,index_length from information_schema.tables where table_schema="test" and table_name="t1";
+drop table t1;