analyzedb

A utility that performs ANALYZE operations on tables incrementally and concurrently.

Synopsis

analyzedb -d <dbname> -s <schema>
   [ --full ]    
   [ -l | --list ]
   [ -p <parallel-level> ]
   [ -v | --verbose ]
   [ -a ]

analyzedb -d <dbname> -t <schema>.<table> 
   [ -i col1[, col2, ...] | -x col1[, col2, ...] ]
   [ --full ]
   [ -l | --list ]
   [ -p <parallel-level> ]
   [ -v | --verbose ]
   [ -a ]

analyzedb -d <dbname> -f <config-file> | --file <config-file>
   [ --full ]
   [ -l | --list ]
   [ -p <parallel-level> ]
   [ -v | --verbose ]  
   [ -a ]

analyzedb -d <dbname> --clean_last | --clean_all 

analyzedb --version

analyzedb  -? | -h | --help

Description

The analyzedb utility updates statistics on table data for the specified tables in a HAWQ database incrementally and concurrently.

While performing ANALYZE operations, analyzedb creates a snapshot of the table metadata and stores it on disk on the master host. An ANALYZE operation is performed only if the table has been modified. If a table or partition has not been modified since the last time it was analyzed, analyzedb automatically skips the table or partition because it already contains up-to-date statistics.

For a partitioned table analyzedb analyzes only those partitions that have no statistics, or that have stale statistics. analyzedb also refreshes the statistics on the root partition.

By default, analyzedb creates a maximum of 5 concurrent sessions to analyze tables in parallel. For each session, analyzedb issues an ANALYZE command to the database and specifies different table names. The -p option controls the maximum number of concurrent sessions.

Notes

The utility determines if a table has been modified by comparing catalog metadata of tables with the snapshot of metadata taken during a previous analyzedb operation. The snapshots of table metadata are stored as state files in the directory db_analyze in the HAWQ master data directory. You can specify the --clean_last or --clean_all option to remove state files generated by analyzedb.

If you do not specify a table, set of tables, or schema, the analyzedb utility collects the statistics as needed on all system catalog tables and user-defined tables in the database.

External tables are not affected by analyzedb.

Table names that contain spaces are not supported.

Arguments

-d <dbname>
Specifies the name of the database that contains the tables to be analyzed. If this option is not specified, the database name is read from the environment variable PGDATABASE. If PGDATABASE is not set, the user name specified for the connection is used.

-s <schema>
Specify a schema to analyze. All tables in the schema will be analyzed. Only a single schema name can be specified on the command line.

Only one of the options can be used to specify the files to be analyzed: -f or --file, -t , or -s.

-t <schema>.<table>
Collect statistics only on <schema>.<table>. The table name must be qualified with a schema name. Only a single table name can be specified on the command line. You can specify the -f option to specify multiple tables in a file or the -s option to specify all the tables in a schema.

Only one of these options can be used to specify the files to be analyzed: -f or --file, -t , or -s.

-f, --file <config-file>
Text file that contains a list of tables to be analyzed. A relative file path from current directory can be specified.

The file lists one table per line. Table names must be qualified with a schema name. Optionally, a list of columns can be specified using the -i or -x. No other options are allowed in the file. Other options such as --full must be specified on the command line.

Only one of the options can be used to specify the files to be analyzed: -f or --file, -t , or -s.

When performing ANALYZE operations on multiple tables, analyzedb creates concurrent sessions to analyze tables in parallel. The -p option controls the maximum number of concurrent sessions.

In the following example, the first line performs an ANALYZE operation on the table public.nation, the second line performs an ANALYZE operation only on the columns l_shipdate and l_receiptdate in the table public.lineitem.

public.nation
public.lineitem -i l_shipdate, l_receiptdate

Options

-x <col1>, <col2>, …
Optional. Must be specified with the -t option. For the table specified with the -t option, exclude statistics collection for the specified columns. Statistics are collected only on the columns that are not listed.

Only -i, or -x can be specified. Both options cannot be specified.

-i <col1>, <col2>, …
Optional. Must be specified with the -t option. For the table specified with the -t option, collect statistics only for the specified columns.

Only -i, or -x can be specified. Both options cannot be specified.

--full
Perform an ANALYZE operation on all the specified tables. The operation is performed even if the statistics are up to date.

-l, --list
Lists the tables that would have been analyzed with the specified options. The ANALYZE operations are not performed.

-p <parallel-level>
The number of tables that are analyzed in parallel. The value for can be an integer between 1 and 10, inclusive. Default value is 5.

-a
Quiet mode. Do not prompt for user confirmation.

-v, --verbose
If specified, sets the logging level to verbose. Additional log information is written to the log file and the command line during command execution.

--clean_last
Remove the state files generated by last analyzedb operation. All other options except -d are ignored.

--clean_all
Remove all the state files generated by analyzedb. All other options except-d are ignored.

-h, -?, --help
Displays the online help.

--version
Displays the version of this utility.

Examples

An example that collects statistics only on a set of table columns. In the database mytest, collect statistics on the columns shipdate and receiptdate in the table public.orders:

$ analyzedb -d mytest -t public.orders -i shipdate, receiptdate

An example that collects statistics on a table and exclude a set of columns. In the database mytest, collect statistics on the table public.foo, and do not collect statistics on the columns bar and test2.

$ analyzedb -d mytest -t public.foo -x bar, test2

An example that specifies a file that contains a list of tables. This command collect statistics on the tables listed in the file analyze-tables in the database named mytest.

$ analyzedb -d mytest -f analyze-tables

If you do not specify a table, set of tables, or schema, the analyzedb utility collects the statistics as needed on all catalog tables and user-defined tables in the specified database. This command refreshes table statistics on the system catalog tables and user-defined tables in the database mytest.

$ analyzedb -d mytest