Adding Rows_examined and Rows_sent implementation from 5.6

Summary:
These two fields were added to 5.6 but missing in 8.0.  I noticed
previous implementation was buggy so added a new implementation which is
capturing more rows_examine operations.
There were also no MTR tests so I added new tests to cover these fields.

Differential Revision: D15999862

mysql-test/include/counter_rows.inc

@@ -0,0 +1,22 @@
+# Executes sql command and validates the values of Rows_examined and Rows_sent
+# values from status table.
+# The following variables should be set before invoking this inc file
+
+# Start counters
+--let $start_rows_examined = query_get_value(show status like "Rows_examined", Value, 1)
+--let $start_rows_sent = query_get_value(show status like "Rows_sent", Value, 1)
+
+--eval $sql
+
+# Get counters
+--let $end_rows_examined = query_get_value(show status like "Rows_examined", Value, 1)
+--let $end_rows_sent = query_get_value(show status like "Rows_sent", Value, 1)
+
+# Check sanity
+--let $assert_text= Rows_examined should be increased by $expected_rows_examined.
+--let $assert_cond= $end_rows_examined - $start_rows_examined = $expected_rows_examined
+--source include/assert.inc
+
+--let $assert_text= Rows_sent should be increased by $expected_rows_sent.
+--let $assert_cond= $end_rows_sent - $start_rows_sent = $expected_rows_sent
+--source include/assert.inc

mysql-test/r/counter_rows.result

@@ -0,0 +1,45 @@
+flush status;
+Variation 0: Return constant value. 
+select 1;;
+1
+1
+include/assert.inc [Rows_examined should be increased by 1.]
+include/assert.inc [Rows_sent should be increased by 1.]
+Variation 1: Create Table. 
+CREATE TABLE t1 (a INT) ENGINE=InnoDB;;
+include/assert.inc [Rows_examined should be increased by 0.]
+include/assert.inc [Rows_sent should be increased by 0.]
+Variation 2: Insert one row into Table. 
+INSERT INTO t1 VALUES (1);;
+include/assert.inc [Rows_examined should be increased by 0.]
+include/assert.inc [Rows_sent should be increased by 0.]
+Variation 3: Select one row from Table. 
+SELECT * FROM t1;;
+a
+1
+include/assert.inc [Rows_examined should be increased by 1.]
+include/assert.inc [Rows_sent should be increased by 1.]
+Variation 4: Update one row. 
+UPDATE t1 SET a = 1;;
+include/assert.inc [Rows_examined should be increased by 1.]
+include/assert.inc [Rows_sent should be increased by 0.]
+Variation 5: SELECT with JOIN 
+SELECT * FROM t1 AS a1 JOIN t1 AS a2 ON a1.a = a2.a;;
+a a
+1 1
+include/assert.inc [Rows_examined should be increased by 2.]
+include/assert.inc [Rows_sent should be increased by 1.]
+Variation 6: UNION 
+SELECT * FROM t1 AS a1 LEFT JOIN t1 AS a2 ON a1.a = a2.a UNION SELECT * FROM t1 AS a1 RIGHT JOIN t1 AS a2 ON a1.a = a2.a;;
+a a
+1 1
+include/assert.inc [Rows_examined should be increased by 5.]
+include/assert.inc [Rows_sent should be increased by 1.]
+Variation 7: DELETE rows from Table. 
+DELETE FROM t1;;
+include/assert.inc [Rows_examined should be increased by 1.]
+include/assert.inc [Rows_sent should be increased by 0.]
+Variation 8: Drop Table. 
+DROP TABLE t1;;
+include/assert.inc [Rows_examined should be increased by 0.]
+include/assert.inc [Rows_sent should be increased by 0.]

mysql-test/t/counter_rows.test

@@ -0,0 +1,90 @@
+#Set all to zero
+flush status;
+
+#
+--echo Variation 0: Return constant value. 
+#
+
+--let $sql = select 1;
+--let $expected_rows_examined = 1
+--let $expected_rows_sent = 1
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 1: Create Table. 
+#
+
+--let $sql = CREATE TABLE t1 (a INT) ENGINE=InnoDB;
+--let $expected_rows_examined = 0
+--let $expected_rows_sent = 0
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 2: Insert one row into Table. 
+#
+
+--let $sql = INSERT INTO t1 VALUES (1);
+--let $expected_rows_examined = 0
+--let $expected_rows_sent = 0
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 3: Select one row from Table. 
+#
+
+--let $sql = SELECT * FROM t1;
+--let $expected_rows_examined = 1
+--let $expected_rows_sent = 1
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 4: Update one row. 
+#
+
+--let $sql = UPDATE t1 SET a = 1;
+--let $expected_rows_examined = 1
+--let $expected_rows_sent = 0
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 5: SELECT with JOIN 
+#
+
+--let $sql = SELECT * FROM t1 AS a1 JOIN t1 AS a2 ON a1.a = a2.a;
+--let $expected_rows_examined = 2
+--let $expected_rows_sent = 1
+--source include/counter_rows.inc
+
+#
+--echo Variation 6: UNION 
+#
+
+--let $sql = SELECT * FROM t1 AS a1 LEFT JOIN t1 AS a2 ON a1.a = a2.a UNION SELECT * FROM t1 AS a1 RIGHT JOIN t1 AS a2 ON a1.a = a2.a;
+--let $expected_rows_examined = 5
+--let $expected_rows_sent = 1
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 7: DELETE rows from Table. 
+#
+
+--let $sql = DELETE FROM t1;
+--let $expected_rows_examined = 1
+--let $expected_rows_sent = 0
+--source include/counter_rows.inc
+
+
+#
+--echo Variation 8: Drop Table. 
+#
+
+--let $sql = DROP TABLE t1;
+--let $expected_rows_examined = 0
+--let $expected_rows_sent = 0
+--source include/counter_rows.inc

sql/mysqld.cc

@@ -12010,6 +12010,10 @@ SHOW_VAR status_vars[] = {
  SHOW_SCOPE_GLOBAL},
  {"Relay_log_sql_wait_seconds", (char *)&relay_sql_wait_time, SHOW_TIMER,
  SHOW_SCOPE_GLOBAL},
+ {"Rows_examined", (char *)offsetof(System_status_var, rows_examined),
+ SHOW_LONGLONG_STATUS, SHOW_SCOPE_GLOBAL},
+ {"Rows_sent", (char *)offsetof(System_status_var, rows_sent),
+ SHOW_LONGLONG_STATUS, SHOW_SCOPE_GLOBAL},
  {"Secondary_engine_execution_count",
  (char *)offsetof(System_status_var, secondary_engine_execution_count),
  SHOW_LONGLONG_STATUS, SHOW_SCOPE_ALL},

sql/sql_class.cc

@@ -2496,11 +2496,13 @@ void THD::set_sent_row_count(ha_rows count) {
 
 void THD::inc_sent_row_count(ha_rows count) {
  m_sent_row_count += count;
+ status_var.rows_sent += count;
  MYSQL_SET_STATEMENT_ROWS_SENT(m_statement_psi, m_sent_row_count);
 }
 
 void THD::inc_examined_row_count(ha_rows count) {
  m_examined_row_count += count;
+ status_var.rows_examined += count;
  MYSQL_SET_STATEMENT_ROWS_EXAMINED(m_statement_psi, m_examined_row_count);
 }
 

sql/system_variables.h

@@ -603,6 +603,8 @@ struct System_status_var {
  ulonglong com_stmt_fetch;
  ulonglong com_stmt_reset;
  ulonglong com_stmt_close;
+ ulonglong rows_examined;
+ ulonglong rows_sent;
 
  ulonglong bytes_received;
  ulonglong bytes_sent;