d07fc3076b
### What changes were proposed in this pull request? This pr add support analyze all tables in a specific database: ```g4 ANALYZE TABLES ((FROM | IN) multipartIdentifier)? COMPUTE STATISTICS (identifier)? ``` ### Why are the changes needed? 1. Make it easy to analyze all tables in a specific database. 2. PostgreSQL has a similar implementation: https://www.postgresql.org/docs/12/sql-analyze.html. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? The feature tested by unit test. The documentation tested by regenerating the documentation: menu-sql.yaml | sql-ref-syntax-aux-analyze-tables.md -- | --  |  Closes #30648 from wangyum/SPARK-33687. Authored-by: Yuming Wang <yumwang@ebay.com> Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
111 lines
4.1 KiB
Markdown
111 lines
4.1 KiB
Markdown
---
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layout: global
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title: ANALYZE TABLES
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displayTitle: ANALYZE TABLES
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license: |
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Licensed to the Apache Software Foundation (ASF) under one or more
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contributor license agreements. See the NOTICE file distributed with
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this work for additional information regarding copyright ownership.
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The ASF licenses this file to You under the Apache License, Version 2.0
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(the "License"); you may not use this file except in compliance with
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the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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---
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### Description
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The `ANALYZE TABLES` statement collects statistics about all the tables in a specified database to be used by the query optimizer to find a better query execution plan.
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### Syntax
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```sql
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ANALYZE TABLES [ { FROM | IN } database_name ] COMPUTE STATISTICS [ NOSCAN ]
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```
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### Parameters
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* **{ FROM `|` IN } database_name**
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Specifies the name of the database to be analyzed. Without a database name, `ANALYZE` collects all tables in the current database that the current user has permission to analyze.
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* **[ NOSCAN ]**
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Collects only the table's size in bytes (which does not require scanning the entire table).
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### Examples
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```sql
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CREATE DATABASE school_db;
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USE school_db;
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CREATE TABLE teachers (name STRING, teacher_id INT);
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INSERT INTO teachers VALUES ('Tom', 1), ('Jerry', 2);
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CREATE TABLE students (name STRING, student_id INT, age SHORT);
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INSERT INTO students VALUES ('Mark', 111111, 10), ('John', 222222, 11);
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ANALYZE TABLES IN school_db COMPUTE STATISTICS NOSCAN;
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DESC EXTENDED teachers;
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+--------------------+--------------------+-------+
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| col_name| data_type|comment|
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+--------------------+--------------------+-------+
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| name| string| null|
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| teacher_id| int| null|
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| ...| ...| ...|
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| Provider| parquet| |
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| Statistics| 1382 bytes| |
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| ...| ...| ...|
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+--------------------+--------------------+-------+
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DESC EXTENDED students;
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+--------------------+--------------------+-------+
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| col_name| data_type|comment|
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+--------------------+--------------------+-------+
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| name| string| null|
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| student_id| int| null|
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| age| smallint| null|
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| ...| ...| ...|
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| Statistics| 1828 bytes| |
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| ...| ...| ...|
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+--------------------+--------------------+-------+
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ANALYZE TABLES COMPUTE STATISTICS;
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DESC EXTENDED teachers;
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+--------------------+--------------------+-------+
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| col_name| data_type|comment|
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+--------------------+--------------------+-------+
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| name| string| null|
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| teacher_id| int| null|
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| ...| ...| ...|
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| Provider| parquet| |
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| Statistics| 1382 bytes, 2 rows| |
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| ...| ...| ...|
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+--------------------+--------------------+-------+
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DESC EXTENDED students;
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+--------------------+--------------------+-------+
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| col_name| data_type|comment|
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+--------------------+--------------------+-------+
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| name| string| null|
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| student_id| int| null|
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| age| smallint| null|
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| ...| ...| ...|
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| Provider| parquet| |
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| Statistics| 1828 bytes, 2 rows| |
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| ...| ...| ...|
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+--------------------+--------------------+-------+
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```
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### Related Statements
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* [ANALYZE TABLE](sql-ref-syntax-aux-analyze-table.html)
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