layout: global title: ANALYZE TABLE displayTitle: ANALYZE TABLE license: | Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
The ANALYZE TABLE
statement collects statistics about the table to be used by the query optimizer to find a better query execution plan.
{% highlight sql %} ANALYZE TABLE table_identifier [ partition_spec ] COMPUTE STATISTICS [ NOSCAN | FOR COLUMNS col [ , ... ] | FOR ALL COLUMNS ]
{% endhighlight %}
{% highlight sql %} ANALYZE TABLE students COMPUTE STATISTICS NOSCAN;
DESC EXTENDED students; ...... Statistics 2820 bytes ......
ANALYZE TABLE students COMPUTE STATISTICS;
DESC EXTENDED students; ...... Statistics 2820 bytes, 3 rows ......
ANALYZE TABLE students PARTITION (student_id = 111111) COMPUTE STATISTICS;
DESC EXTENDED students PARTITION (student_id = 111111); ...... Partition Statistics 919 bytes, 1 rows ......
ANALYZE TABLE students COMPUTE STATISTICS FOR COLUMNS name;
DESC EXTENDED students name; =default tbl=students col_name name data_type string comment NULL min NULL max NULL num_nulls 0 distinct_count 3 avg_col_len 11 max_col_len 13 histogram NULL
{% endhighlight %}