Estimation for filtered rows less precise with JSON histogram comparing to DOUBLE_PREC (#3)

--source include/have_sequence.inc

# One third are zeros, the rest are unique values

create or replace table t (a tinyint) as select if(seq%3,seq,0) as a from seq_1_to_100;

select count(*) from t where a <= 0;

set histogram_type = JSON_HB;

analyze table t persistent for all;

explain format=json select * from t where a <= 0;

set histogram_type = DOUBLE_PREC_HB;

analyze table t persistent for all;

explain format=json select * from t where a <= 0;

# Cleanup

drop table t;

select count(*) from t where a <= 0;

count(*)

33

{

  "query_block": {

    "select_id": 1,

    "table": {

      "table_name": "t",

      "access_type": "ALL",

      "rows": 100,

      "filtered": 1.470600009,

      "attached_condition": "t.a <= 0"

    }

  }

}

{

  "query_block": {

    "select_id": 1,

    "table": {

      "table_name": "t",

      "access_type": "ALL",

      "rows": 100,

      "filtered": 32.8125,

      "attached_condition": "t.a <= 0"

    }

  }

}