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## • Ndb_api_read_row_count_session 

The total number of rows that have been read in this client session. This includes all rows read by any primary key, unique key, or scan operation made in this client session. 

Although this variable can be read using either SHOW GLOBAL STATUS  or SHOW SESSION STATUS , it relates to the current session only, and is not affected by any other clients of this mysqld . 

For more information, see Section 23.5.13, “NDB API Statistics Counters and Variables” . 

## • Ndb_api_read_row_count_replica 

The total number of rows that have been read by this replica. This includes all rows read by any primary key, unique key, or scan operation made by this replica. 

Although this variable can be read using either SHOW GLOBAL STATUS  or SHOW SESSION STATUS , it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0. 

For more information, see Section 23.5.13, “NDB API Statistics Counters and Variables” . 

## • Ndb_api_read_row_count_slave 

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## Note 

Deprecated in NDB 8.0.23; use Ndb_api_read_row_count_replica  instead. 

The total number of rows that have been read by this replica. This includes all rows read by any primary key, unique key, or scan operation made by this replica. 

Although this variable can be read using either SHOW GLOBAL STATUS  or SHOW SESSION STATUS , it is effectively global in scope. If this MySQL server does not act as a replica, or does not use NDB tables, this value is always 0. 

For more information, see Section 23.5.13, “NDB API Statistics Counters and Variables” . 

## • Ndb_api_read_row_count 

The total number of rows that have been read by this MySQL Server (SQL node). This includes all rows read by any primary key, unique key, or scan operation made by this MySQL Server (SQL node). 

You should be aware that this value may not be completely accurate with regard to rows read by SELECT COUNT(*)  queries, due to the fact that, in this case, the MySQL server actually reads pseudo-rows in the form [ table fragment ID ]:[ number of rows in fragment ]  and sums the rows per fragment for all fragments in the table to derive an estimated count for all rows. Ndb_api_read_row_count  uses this estimate and not the actual number of rows in the table. 

Although this variable can be read using either SHOW GLOBAL STATUS  or SHOW SESSION STATUS , it is effectively global in scope. 

For more information, see Section 23.5.13, “NDB API Statistics Counters and Variables” . 

