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Implement avg_frequency unsmoothed jacknife estimator

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When sampling data through ANALYZE TABLE, use the estimator to get a
better estimation of avg_frequency instead of just using the raw sampled data.
This commit is contained in:
Vicențiu Ciorbaru
2019-02-17 00:44:58 +02:00
parent f0773b7842
commit 764429271d
3 changed files with 96 additions and 31 deletions
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5
mysql-test/main/statistics.test
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@ -912,6 +912,7 @@ set histogram_size=@save_hist_size, histogram_type=@save_hist_type;
--echo #
set @save_use_stat_tables=@@use_stat_tables;
set @save_analyze_sample_percentage=@@analyze_sample_percentage;
set @save_hist_size=@@histogram_size;
set session rand_seed1=42;
set session rand_seed2=62;
@ -986,6 +987,8 @@ select table_name, column_name, min_value, max_value, nulls_ratio, avg_length, a
from mysql.column_stats;
explain select * from t1;
set use_stat_tables=@save_use_stat_tables;
drop table t1;
set analyze_sample_percentage=@save_analyze_sample_percentage;
set histogram_size=@save_hist_size;
set use_stat_tables=@save_use_stat_tables;