text: DROP TABLE IF EXISTS prop_table;
  
  CREATE TABLE prop_table
  (
      column_default UInt64 DEFAULT 42,
      column_materialized UInt64 MATERIALIZED column_default * 42,
      column_alias UInt64 ALIAS column_default + 1,
      column_codec String CODEC(ZSTD(10)),
      column_comment Date COMMENT 'Some comment',
      column_ttl UInt64 TTL column_comment + INTERVAL 1 MONTH
  )
  ENGINE MergeTree()
  ORDER BY tuple()
  TTL column_comment + INTERVAL 2 MONTH;
  
  SHOW CREATE TABLE prop_table;
  
  SYSTEM STOP TTL MERGES prop_table;
  
  INSERT INTO prop_table (column_codec, column_comment, column_ttl) VALUES ('str', toDate('2019-10-01'), 1);
  
  SELECT column_default, column_materialized, column_alias, column_codec, column_comment, column_ttl FROM prop_table;
  
  ALTER TABLE prop_table MODIFY COLUMN column_comment REMOVE COMMENT;
  
  SHOW CREATE TABLE prop_table;
  
  ALTER TABLE prop_table MODIFY COLUMN column_codec REMOVE CODEC;
  
  SHOW CREATE TABLE prop_table;
  
  ALTER TABLE prop_table MODIFY COLUMN column_alias REMOVE ALIAS;
  
  SELECT column_default, column_materialized, column_alias, column_codec, column_comment, column_ttl FROM prop_table;
  
  SHOW CREATE TABLE prop_table;
  
  INSERT INTO prop_table (column_alias, column_codec, column_comment, column_ttl) VALUES (33, 'trs', toDate('2020-01-01'), 2);
  
  SELECT column_default, column_materialized, column_alias, column_codec, column_comment, column_ttl FROM prop_table ORDER BY column_ttl;
  
  ALTER TABLE prop_table MODIFY COLUMN column_materialized REMOVE MATERIALIZED;
  
  SHOW CREATE TABLE prop_table;
  
  INSERT INTO prop_table (column_materialized, column_alias, column_codec, column_comment, column_ttl) VALUES (11, 44, 'rts', toDate('2020-02-01'), 3);
  
  SELECT column_default, column_materialized, column_alias, column_codec, column_comment, column_ttl FROM prop_table ORDER BY column_ttl;
  
  ALTER TABLE prop_table MODIFY COLUMN column_default REMOVE DEFAULT;
  
  SHOW CREATE TABLE prop_table;
  
  INSERT INTO prop_table (column_materialized, column_alias, column_codec, column_comment, column_ttl) VALUES (22, 55, 'tsr', toDate('2020-03-01'), 4);
  
  SELECT column_default, column_materialized, column_alias, column_codec, column_comment, column_ttl FROM prop_table ORDER BY column_ttl;
  
  ALTER TABLE prop_table REMOVE TTL;
  
  SHOW CREATE TABLE prop_table;
  
  ALTER TABLE prop_table MODIFY COLUMN column_ttl REMOVE TTL;
  
  SHOW CREATE TABLE prop_table;
  
  SYSTEM START TTL MERGES prop_table;
  
  OPTIMIZE TABLE prop_table FINAL;
  
  SELECT COUNT() FROM prop_table;
  
  DROP TABLE IF EXISTS prop_table;
  