Enforce read-only sessions on diagnostic scripts#64
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Export PGOPTIONS with default_transaction_read_only=on (plus statement and lock timeouts on the fast diagnostics) so status/preflight/compare checks cannot write and can't hang on a busy source. verify-migration gets read-only only, since it manages its own per-table COUNT(*) timeout.
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Adds a read-only safety belt to the scripts that only ever read, via an exported
PGOPTIONS.What
compare-pg-params.shdefault_transaction_read_only=on+statement_timeout=30s+lock_timeout=5scheck-cdc-status.shcheck-migration-status.shpreflight-check.shverify-migration.shread_onlyonly — it manages its own per-tableCOUNT(*)timeout via--exact-count-timeout, and a shortlock_timeoutcould turn a transient lock on a busy source into a false verification failureWhy
These are diagnostics that should never write.
default_transaction_read_only=onmakes accidental writes impossible even if a query is later edited; the statement/lock timeouts keep a check from hanging on a busy database — important since several query the live source.Notes
export PGOPTIONSafter each script's env load, so every existingpsqlcall inherits it with no per-call changes.read_only=on.bash -npasses on all five.No automated test suite in this repo; validated by syntax check and code inspection.