text: /* Explain */
  /* Basic selection with limit */
  EXPLAIN (COSTS off) SELECT * FROM zips LIMIT 3;
  /* Select less fields than exist */
  EXPLAIN (COSTS off) SELECT city FROM zips LIMIT 1;
  /* Basic WHERE clause */
  EXPLAIN (COSTS off) SELECT * FROM zips WHERE "state" = 'CO' LIMIT 2;
  /* Nested selection */
  EXPLAIN (COSTS off) SELECT * FROM nested LIMIT 1;
  /* less fields than in relation, with one in a WHERE clause */
  EXPLAIN (COSTS off) SELECT city FROM zips WHERE "state" = 'CO' LIMIT 1;
  EXPLAIN (COSTS off) SELECT city,pop FROM zips WHERE pop % 2 = 1 LIMIT 3;
  /* Test out array usage */
  EXPLAIN (COSTS off) SELECT * FROM zipsloc LIMIT 2;
  /* Test out json usage */
  EXPLAIN (COSTS off) SELECT loc->0 AS loc0, locb->1 AS loc1, locb FROM zipsjson LIMIT 2;
  /* Pushdown regex operators */
  EXPLAIN (COSTS off) SELECT * FROM zips WHERE "state" LIKE 'A%' LIMIT 3;
  EXPLAIN (COSTS off) SELECT * FROM zips WHERE "city" !~~ 'B%' LIMIT 3;
  /* pushdown math operators */
  EXPLAIN (COSTS off) SELECT * FROM zips WHERE pop > 1000 AND pop + pop <= 10000 LIMIT 3;
  /* join zips and zipsjson */
  EXPLAIN (COSTS off) SELECT zips.city AS city, zips.pop, state, loc
                      FROM zips JOIN zipsjson
                           ON zips.city = zipsjson.city
                           AND zips.pop = zipsjson.pop
                      LIMIT 3;
  /* query for a missing field */
  EXPLAIN (COSTS off) SELECT missing, city FROM zips_missing LIMIT 3;
  /* No pushdown of `nopushdown` columns */
  EXPLAIN (COSTS off) SELECT * FROM commits WHERE ts = timestamp 'Thu Jan 29 15:52:37 2015';
  /* Pushdown of concat */
  EXPLAIN (COSTS off) SELECT * FROM smallzips WHERE length(concat(state, city)) > 4 AND state LIKE concat('M'::char, '%'::char) LIMIT 5;
  /* pushdown of concat */
  EXPLAIN (COSTS off) SELECT * FROM smallzips
          /* push down concat columns */
          WHERE length(concat(state, city)) > 4
          /* pushed down correctly */
          AND state = concat('M'::char, 'A'::char)
          /* push down concat operator */
          AND 'B' || city LIKE 'B%' LIMIT 5;
  /* LIKE operator only supports constant right sides */
  EXPLAIN (COSTS off) SELECT * FROM smallzips WHERE state LIKE concat('B'::char, '%'::char);
  /* ORDER BY pushdown */
  EXPLAIN (COSTS off) SELECT * FROM zips ORDER BY length(city), pop DESC, state;
  /* Can't pushdown NULLS FIRST */
  EXPLAIN (COSTS off) SELECT * FROM zips ORDER BY state NULLS FIRST;
  /* If one ORDER BY column can't be pushed down, none are */
  EXPLAIN (COSTS off) SELECT * FROM commits ORDER BY ts, sha;
  /* VERBOSE on */
  EXPLAIN (COSTS off, VERBOSE on) SELECT * FROM zips WHERE state = 'CO' ORDER BY pop DESC;
  /* Timestamps and dates pushdown */
  EXPLAIN (COSTS off) SELECT * FROM commits_timestamps WHERE ts < TIMESTAMP '2015-01-20T00:00:00Z' LIMIT 2;
  EXPLAIN (COSTS off) SELECT * FROM commits_timestamps WHERE ts < DATE '2015-01-20' LIMIT 2;
  EXPLAIN (COSTS off) SELECT * FROM commits_timestamps WHERE tstz < TIMESTAMPTZ '2015-01-15 19:43:04 PST';
  EXPLAIN (COSTS off) SELECT * FROM commits_timestamps ORDER BY ts DESC LIMIT 2;
  EXPLAIN (COSTS off) SELECT * FROM test_times WHERE t < TIME '11:04:23.551';
  /* Intervals less than 1 month are pushed down to quasar */
  EXPLAIN (COSTS off) SELECT * FROM test_intervals WHERE i < INTERVAL '7 days 4 hours 5 minutes';
  /* Intervals > 1 month can't be pushed down because quasar doesn't handle them */
  EXPLAIN (COSTS off) SELECT * FROM test_intervals WHERE i > INTERVAL '1 year';
  /* Aggregations */
  EXPLAIN (COSTS off) SELECT count(*) FROM smallzips;
  EXPLAIN (COSTS off) SELECT count(*) FROM zips WHERE state IN ('CA','OR','WA');
  /* Array subscripts push down correctly from 1-based to 0-based */
  EXPLAIN (COSTS off) SELECT loc FROM zipsloc WHERE loc[1] < 0;
  EXPLAIN (COSTS off) SELECT loc FROM zipsloc WHERE loc[1+1] > 0;
  /* Scalar array ops */
  EXPLAIN (COSTS off) SELECT * FROM smallzips WHERE state IN ('MA', 'CA');
  EXPLAIN (COSTS off) SELECT * FROM smallzips WHERE state IN ('MA');
  