MDEV-24658: Optimizer trace reads a column not marked for read#5321
MDEV-24658: Optimizer trace reads a column not marked for read#5321DaveGosselin-MariaDB wants to merge 1 commit into
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This pull request addresses MDEV-24658 where the optimizer trace reads a column not marked for read. The fix updates Field::marked_for_read() in sql/field.cc to return true if the table is a constant table (table->const_table), as its row is read during optimization and remains materialized in record[0]. Additionally, a corresponding test case has been added to mysql-test/main/opt_trace.test and its expected output updated in mysql-test/main/opt_trace.result. There are no review comments to address, and I have no further feedback to provide.
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When the optimizer trace is enabled, it's safe to read from a constant table because the value in record[0] was materialized during optimization and remains available, even after constants propagation has removed the table from the read set.
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When the optimizer trace is enabled, it's safe to read from a constant table because the value in record[0] was materialized during optimization and remains available, even after constants propagation has removed the table from the read set.