Check Table

Check Table

Purpose

Checking a TokuDB table verifies a set of fractal tree invariants for all fractal trees that are used to store data for the table. One example invariant is that all of the rows are stored sorted in key order.

Concurrency

MySQL 5.5 schedules check table with a shared read meta data lock. The MDL_SHARED_READ and TL_READ_NO_INSERT meta data locking levels are used. This lock allows concurrent reads to the table, but prohibits concurrent writes to the table, while the table is being checked.

Processlist Info

Since check table scans all of the rows stored in all of the fractal trees for a table, it can take a long time. Check table periodically updates the process info with the state of the check table operation.