MySQL throws error 1074 when a column definition exceeds the maximum allowed length for its data type or storage engine.
MySQL Error 1074: ER_TOO_BIG_FIELDLENGTH arises when a column definition is larger than the engine's limit. Reduce the column size, switch to BLOB/TEXT, or pick a compatible row format to resolve the issue.
Column length too big for column '%s' (max = %lu); use
Error 1074 (SQLSTATE 42000) appears when a CREATE or ALTER TABLE statement defines a column whose length exceeds the storage engine's hard limit. InnoDB limits VARCHAR to 65,535 bytes per row, and each row must fit into a single page unless DYNAMIC/COMPRESSED row format is used.
The message hints at using BLOB or TEXT because those types are stored off-page, keeping the row size below the limit.
Ignoring the error blocks DDL execution, so you must correct the definition before the statement can run.
The error surfaces during table creation, column alteration, or index addition that implicitly changes column length.
It frequently occurs after migrating schemas from other databases or auto-generated ORMs that default to large VARCHAR sizes.
MySQL 5.7 and later are more strict about oversized columns, especially when utf8mb4 is the default character set because each character may consume up to four bytes.
Blocking DDL prevents new tables from being deployed and halts application releases. Large column definitions can also hurt performance and waste memory.
Resolving the error ensures stable deployments, optimal storage, and index efficiency.
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Switching from utf8 to utf8mb4 quadruples potential byte usage per character, pushing VARCHAR lengths over the 65,535-byte limit.
Defining several VARCHAR(255) or larger columns in the same table can breach the per-row limit even if each individual column is within bounds.
Using COMPACT or REDUNDANT row formats forces long VARCHAR values to stay on-page, triggering the size check.
Tools that translate schemas from Oracle or SQL Server often map CLOB or NVARCHAR(MAX) to oversized VARCHAR in MySQL.
ENUM with thousands of options inflates internal storage, unexpectedly hitting the byte limit.
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In-place DDL in MySQL 8.0 reduces downtime, but large tables may still lock writes briefly. Test in staging and schedule during low traffic.
191 characters is safe for indexed columns because 191 * 4 bytes fits InnoDB's 767-byte prefix limit.
No. MySQL evaluates potential maximum length, not current data, and will prevent the DDL from executing until the definition is corrected.
Galaxy's schema-aware AI warns when a column size risks exceeding MySQL limits and suggests converting to TEXT or reducing length directly in the editor.
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