in core/src/main/scala/org/apache/pekko/persistence/r2dbc/query/scaladsl/QueryDao.scala [102:112]
private def selectBucketsSql(minSlice: Int, maxSlice: Int): String = {
sql"""
SELECT extract(EPOCH from db_timestamp)::BIGINT / 10 AS bucket, count(*) AS count
FROM $journalTable
WHERE entity_type = ?
AND ${sliceCondition(minSlice, maxSlice)}
AND db_timestamp >= ? AND db_timestamp <= ?
AND deleted = false
GROUP BY bucket ORDER BY bucket LIMIT ?
"""
}