Varun Gupta cd33280b68 MDEV-16374: Filtered shows 0 for materilization scan for a semi join, which makes optimizer always picks ...

materialization scan over materialization lookup

For non-mergeable semi-joins we don't store the estimates of the IN subquery in table->file->stats.records.
In the function TABLE_LIST::fetch_number_of_rows, we store the number of rows in the tables
(estimates in case of derived table/views).
Currently we don't store the estimates for non-mergeable semi-joins, which leads to a problem of selecting
materialization scan over materialization lookup.
Fixed this by storing these estimated appropriately

2018-06-09 11:40:28 +05:30

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