MySQL raises ER_CANNOT_DISCARD_TEMPORARY_TABLE (SQLSTATE HY000, error 3007) when you attempt to DISCARD or IMPORT the tablespace of a temporary table.
ER_CANNOT_DISCARD_TEMPORARY_TABLE appears when MySQL rejects a DISCARD TABLESPACE or IMPORT TABLESPACE command on a temporary table. Convert the table to a regular InnoDB table or drop and recreate it to resolve the error.
ER_CANNOT_DISCARD_TEMPORARY_TABLE
MySQL throws ER_CANNOT_DISCARD_TEMPORARY_TABLE (error 3007, SQLSTATE HY000) when a DISCARD TABLESPACE or IMPORT TABLESPACE statement targets a temporary table. MySQL forbids this operation because temporary tables use session-specific storage that is automatically removed when the session ends.
The error started appearing in MySQL 5.7.1 alongside expanded InnoDB tablespace management commands. Fixing it is essential because failed DDL leaves tables unchanged and can block automation scripts.
The root cause is always an ALTER TABLE ... DISCARD TABLESPACE or ALTER TABLE ... IMPORT TABLESPACE issued against a table defined with the TEMPORARY keyword or created internally by the optimizer as a temporary object.
It can also surface when a script builds the temporary table in one connection and tries to discard the tablespace in another, or when a migration tool mistakenly treats #sql internal temporary names as permanent tables.
Stop running DISCARD or IMPORT on temporary tables. Convert the table to a permanent InnoDB table, or simply drop and recreate it. Use CREATE TABLE ... LIKE to copy the structure, then INSERT INTO ... SELECT to move data before discarding the tablespace.
Automation scripts should check INFORMATION_SCHEMA.TABLES to verify TABLE_TYPE='BASE TABLE' before issuing DISCARD or IMPORT statements.
During online schema migrations, gh-ost or pt-online-schema-change can misidentify swap tables as temporary. Configure the tool to skip DISCARD commands on names beginning with _tmp or use --no-drop-original flags.
In ETL jobs, developers sometimes mark staging tables as TEMPORARY for speed, then clean up with DISCARD. Replace DISCARD with DROP TABLE for these workflows.
Never issue tablespace operations on TEMPORARY tables. Maintain naming conventions that clearly separate temp tables (prefix tmp_) from permanent ones. Add checks in CI pipelines to block dangerous DDL on temp objects.
Use Galaxy's AI copilot to lint migration scripts; it highlights unsupported DISCARD/IMPORT statements on temporary tables before they hit production.
ER_TABLESPACE_DISCARDED (1815) appears when you try to access a table after its tablespace has been discarded. Import the tablespace or restore from backup. ER_INNODB_NO_TABLESPACE (1814) shows when a tablespace file is missing entirely; recreate or recover the .ibd file.
This direct misuse triggers the error instantly.
Import expects a permanent .ibd file which temp tables lack.
Automated renames can lead to accidental DISCARD on #sql temporary tables.
One session creates the temp table, another attempts DISCARD after the original session ends.
Occurs when accessing a table whose tablespace was already discarded.
Raised when InnoDB cannot find the .ibd file for a table.
Appears during IMPORT TABLESPACE if the destination table already exists.
No. Temporary tables have session-bound, transient storage. MySQL prevents DISCARD and IMPORT to protect engine integrity.
Use DROP TEMPORARY TABLE or let the session close. Both actions free the space without touching .ibd files.
No. The restriction applies regardless of global tablespace settings.
Galaxy's linter detects invalid DISCARD/IMPORT statements on temporary tables and suggests safe alternatives, reducing production errors.
.avif)
.avif){kind=logo}
