Bind integer parameters as strings on MySQL connections

[adhikjoshi]

Problem

MySQL 9.0.1 re-prepares a statement server-side on every execute that carries an integer-typed binary-protocol parameter. Production: 226 Com_stmt_reprepare/s — 54% of all statement executes — each one a full re-parse + re-plan of the statement on the DB server, in the same prepared-statement subsystem that produced the 1461 max_prepared_stmt_count outage.

Isolated with a clean-room PDO probe (same-DC VPS, 0.14ms RTT, EMULATE_PREPARES=false):

bind type	reprepares	per query
PDO::PARAM_INT	3000/3000	350–401µs
PDO::PARAM_STR (same value)	0/3000	322–326µs

~15–50µs of server CPU per int-bound query, scaling with statement size. mysql-connector-python with int params does not trigger it — this is specific to how mysqlnd types parameters. MySQL 8.0.36 with the identical stack: zero reprepares.

Fix

MySqlStringBindingConnection overrides bindValues() to send PHP ints as decimal strings with PARAM_STR (otherwise byte-identical to the framework's implementation), registered via Connection::resolverFor('mysql', …). Escape hatch: OCTANE_MYSQL_STRING_BINDINGS=false (also 0/off/no).

A string parameter is converted to the column type with full precision at execute time — verified exact for adjacent bigints beyond 2^53, where a quoted literal would compare as DOUBLE. E2E on Octane + Swoole: an 18-probe battery (inserts, whereIn, whereIntegerInRaw, paginate, limit/offset, aggregates, joins, update/delete counts, PHP_INT_MAX roundtrip) is byte-identical main vs branch; against prod 9.0.1 the per-request reprepare probe goes 1-per-int-query → 0.

Semantic footnote: an int bound against a varchar column previously compared numerically ('05' matched 5, index defeated) and now compares as a string (exact, indexed). Every id-like varchar/char column in modelslab_prod and gpulab_prod was scanned for non-canonical numeric values: zero found.

Tests

• Strict-typed unit tests on the override (mutation-tested: reverting stringification errors both), resolver registration test (mutation-tested: removing registration fails it).
• Full suite: 174 green.
• Adversarially reviewed; the gate-spelling bug and a wrong comment mechanism it found are fixed in the second commit.

🤖 Generated with Claude Code

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