Analyse de requêtes (Digest)

Digest collection

PmaControl integrates Performance Schema to collect and analyze SQL queries:

• Automatic collection via Digest::integrate() triggered by the Listener
• Query normalization (Query::normalize()) to group variants
• SHA-256 digest computation (statement_digest)
• Automatic table extraction from SQL queries

Analysis and EXPLAIN

For each digest, PmaControl provides:

• Execution count, total time, average time, rows examined, rows sent
• Visual EXPLAIN (Myxplain.php) with full-scan and missing index detection
• Performance history to detect regressions
• Server comparison (same digest on master vs replica)

Performance Schema configuration

To enable digest collection, Performance Schema must be enabled:

[mysqld]
performance_schema = ON
performance_schema_digests_size = 10000
performance_schema_max_digest_length = 1024