Class CommitStats (6.83.0)

Commit statistics are returned by a read/write transaction if specifically requested by passing in Options#commitStats() to the transaction.

The number of mutations that were executed by the transaction. Insert and update operations count with the multiplicity of the number of columns they affect. For example, inserting a new record may count as five mutations, if values are inserted into five columns. Delete and delete range operations count as one mutation regardless of the number of columns affected. Deleting a row from a parent table that has the ON DELETE CASCADE annotation is also counted as one mutation regardless of the number of interleaved child rows present. The exception to this is if there are secondary indexes defined on rows being deleted, then the changes to the secondary indexes are counted individually. For example, if a table has 2 secondary indexes, deleting a range of rows in the table counts as 1 mutation for the table, plus 2 mutations for each row that is deleted because the rows in the secondary index might be scattered over the key-space, making it impossible for Cloud Spanner to call a single delete range operation on the secondary indexes. Secondary indexes include the foreign keys backing indexes.