EC
1118
MySQLERRORNotableDDLHIGH confidence

Row size too large (> 8126 bytes for InnoDB default row format)

Production Risk

Medium — DDL fails; existing data is unaffected but schema cannot be changed.

What this means

ER_TOO_BIG_ROWSIZE (1118, SQLSTATE HY000) is raised when the combined size of all fixed-length columns in a table exceeds the maximum row size for the storage engine. For InnoDB with REDUNDANT/COMPACT row format, the limit is approximately 8126 bytes.

Why it happens
  1. 1Many VARCHAR or fixed-length columns whose total exceeds the row size limit
  2. 2Using REDUNDANT or COMPACT row format instead of DYNAMIC or COMPRESSED
  3. 3Very wide tables with many fixed-length columns
How to reproduce
trigger — this will error
trigger — this will error
CREATE TABLE t (
  c1 VARCHAR(500), c2 VARCHAR(500), c3 VARCHAR(500),
  c4 VARCHAR(500), c5 VARCHAR(500), c6 VARCHAR(500),
  c7 VARCHAR(500), c8 VARCHAR(500), c9 VARCHAR(500),
  c10 VARCHAR(500), c11 VARCHAR(500), c12 VARCHAR(500),
  c13 VARCHAR(500), c14 VARCHAR(500), c15 VARCHAR(500),
  c16 VARCHAR(500), c17 VARCHAR(500)
) ROW_FORMAT=COMPACT;

expected output

ERROR 1118 (HY000): Row size too large (> 8126). Changing some columns to TEXT or BLOB may help. In current row format, BLOB prefix of 0 bytes is stored inline.

Fix 1

Switch to DYNAMIC or COMPRESSED row format

WHEN InnoDB table with COMPACT or REDUNDANT row format.

Switch to DYNAMIC or COMPRESSED row format
ALTER TABLE t ROW_FORMAT=DYNAMIC;
-- or set globally:
SET GLOBAL innodb_default_row_format=DYNAMIC;

Why this works

DYNAMIC row format stores long VARCHAR/TEXT columns off-page, allowing much larger effective row sizes.

Fix 2

Convert large VARCHAR columns to TEXT

WHEN Row format change is not possible.

Convert large VARCHAR columns to TEXT
ALTER TABLE t MODIFY COLUMN large_col TEXT;

Why this works

TEXT columns are stored off-page in InnoDB by default (in DYNAMIC format), removing them from the inline row size calculation.

What not to do

✕ Silently truncate data to fit within the row size limit

Truncating data silently loses information; fix the schema instead.

Version notes
MySQL 5.7

innodb_default_row_format was introduced with a default of DYNAMIC, making 1118 less common on new tables.

Sources
Official documentation ↗

MySQL 8.0 — 1118 ER_TOO_BIG_ROWSIZE

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