Reviewed 3 of 5 files at r1, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @ajwerner, @Azhng, and @mgartner)

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 27 at r1 (raw file):

//  value.
var (
	// N.B.: statement and transaction statistics system tables has hash sharded

nit: have

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 69 at r1 (raw file):

				(
		      aggregated_ts,
					fingerprint_id,

nit: alignment

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 73 at r1 (raw file):

		      plan_hash,
		      app_name,
		      node_id                   

nit: remove trailing space

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 89 at r1 (raw file):

				(
		      aggregated_ts,
					fingerprint_id,

nit: alignment

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 91 at r1 (raw file):

					fingerprint_id,
		      app_name,
		      node_id                   

nit: remove trailing space

pkg/sql/sqlstats/persistedsqlstats/compaction_test.go line 216 at r1 (raw file):

				// The two interceptors (kvInterceptor and cleanupInterceptor) are
				// injected into kvserver and StatsCompactor respectively.
				// The cleanupInterceptor calculates number of expected "wide scan"

nit: calculates the number

pkg/sql/sqlstats/persistedsqlstats/compaction_test.go line 218 at r1 (raw file):

				// The cleanupInterceptor calculates number of expected "wide scan"
				// that should be issued by the StatsCompactor.
				// The kvInterceptor counts number of actual "wide scan" KV Request

nit: counts the number

Reviewed 5 of 5 files at r1, all commit messages.
Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @ajwerner and @Azhng)

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 168 at r1 (raw file):

		for remainToBeRemoved := rowsToRemove; remainToBeRemoved > 0; {
			if len(lastDeletedRow) > 0 {
				stmt = ops.subsequentDeleteStmt

nit: It might be clearer to create a method of cleanupOperations that returns the stmt given lastDeletedRow - if lastDeletedRow was empty it could return the wide version, otherwise the constrained version.

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 224 at r1 (raw file):

func getQargs(shardIdx, limit int64, lastDeletedRow tree.Datums) []interface{} {
	qargs := make([]interface{}, 0, len(lastDeletedRow)+2)

nit: you could make this a scratch field in StatsCompactor to reduce allocations.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 117 at r1 (raw file):

		}
	case "system.transaction_statistics":
		return &cleanupOperations{

You could defined these structs are singletons that can be accessed directly without the need of this cleanupOpForTable helper. I think it'd be nice to have the constrained and unconstrained queries side by side for reference.

Also moved query_utils.go back into compaction_exec.go

Reviewable status: complete! 0 of 0 LGTMs obtained (waiting on @ajwerner, @maryliag, and @mgartner)

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 168 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 224 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/compaction_test.go line 216 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/compaction_test.go line 218 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 27 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 69 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 73 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 89 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 91 at r1 (raw file):

Done.

pkg/sql/sqlstats/persistedsqlstats/query_utils.go line 117 at r1 (raw file):

Done.

Reviewed 4 of 4 files at r2, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @ajwerner and @Azhng)

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 165 at r2 (raw file):

) error {
	var err error
	lastDeletedRow := tree.Datums{}

nit: var lastDeletedRow tree.Datums should be sufficient here.

pkg/sql/sqlstats/persistedsqlstats/compaction_exec.go line 284 at r2 (raw file):

	deleteFromStmtStatsWithWideScan = `
    DELETE FROM system.statement_statistics

nit: you could move these strings into the structs defined below to avoid a reader having to follow a trail to make sense of this.

Reviewed 2 of 4 files at r2, all commit messages.
Reviewable status: complete! 2 of 0 LGTMs obtained (waiting on @ajwerner and @Azhng)