Expensive SQL query inside ensureVersionTable & ensureLockTable

[deepakd10]

Is your feature request related to a problem? Please describe.

While creating cockroachdb instance via WithInstance(). Checks are made to ensure that version & Lock tables are created.
These two function tap into information_schema.tables. Which is an expensive query. ~15 Sec each.

withinstance() function location ->

migrate/database/cockroachdb/cockroachdb.go

Line 350 in cd17c5a

query := `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`

ensureLockTable() function location ->

migrate/database/cockroachdb/cockroachdb.go

Line 350 in cd17c5a

query := `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`

ensureVersionTable() function location ->

migrate/database/cockroachdb/cockroachdb.go

Line 331 in cd17c5a

query := `SELECT COUNT(1) FROM information_schema.tables WHERE table_name = $1 AND table_schema = (SELECT current_schema()) LIMIT 1`

Describe the solution you'd like

Ideas :

1. Let the user pass-on the query string for both the functions.
2. Introduce another field ValidateTables to Config

type Config struct {
	MigrationsTable string
	LockTable       string
	ForceLock       bool
	DatabaseName    string
	// this will the new field, for users to Enable/Disable validations.
        ValidateTables bool
}

Additional context

If we skip this validation the migration which takes ~30 Secs is reduced to < 1Sec