1633
MariaDBWARNINGCriticalInformation SchemaHIGH confidence
INFORMATION_SCHEMA table was skipped due to timeout or lock
Production Risk
Low — result may be incomplete but no data is modified.
What this means
While gathering information_schema data, one or more tables were skipped because they could not be accessed (e.g., due to a lock or timeout), and the result set may be incomplete.
Why it happens
- 1A metadata lock on the target table prevented information_schema from reading it.
- 2The lock wait timeout expired while information_schema was trying to open the table.
How to reproduce
trigger — this will error
trigger — this will error
SELECT * FROM information_schema.TABLES WHERE table_schema = 'mydb';
expected output
Warning 1633: Table 'mydb.big_table' was skipped since open_tables limit is reached.
Fix 1
Increase table cache size
Increase table cache size
SET GLOBAL table_open_cache = 4000;
Why this works
A larger table cache allows more tables to be opened simultaneously.
Fix 2
Filter the query to specific tables
Filter the query to specific tables
SELECT * FROM information_schema.TABLES WHERE table_schema = 'mydb' AND table_name = 'specific_table';
Why this works
Narrowing the query scope reduces the number of tables that need to be opened.
Sources
Official documentation ↗
MySQL 8.0 — 1633 ER_WARN_I_S_SKIPPED_TABLE
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