How to Show Tables From All Schemas with Presto

In Presto it is straightforward to show all tables in a schema e.g. If we have a MySQL data source/catalog that has a “demo” schema we use show tables in mysql.demo; but this only reveals the tables managed by that data source.

There is no equivalent way to show all tables in all schemas for a data source. However there’s the metastore to fall back on which we can query: In MySQL, Glue, Hive and others there is a schema called “information_schema” which contains a table called “tables”.  This maintains a list of  schemas and tables relating to that data source.

For a MySQL data source, here’s what Presto shows in a Presto table:

presto> select table_schema, table_name from mysql.information_schema.tables order by 1,2;
    table_schema    |                  table_name                   
 demo               | geography                                     
 demo               | state                                         
 demo               | test                                          
 information_schema | applicable_roles                              
 information_schema | columns                                       
 information_schema | enabled_roles                                 
 information_schema | roles                                         
 information_schema | schemata                                      
 information_schema | table_privileges                              
 information_schema | tables                                        
 information_schema | views                                         
 sys                | host_summary                                  
 sys                | host_summary_by_file_io                       
 sys                | host_summary_by_file_io_type                  

For Ahana’s integrated Hive metastore:

presto:demo> select table_schema, table_name from ahana_hive.information_schema.tables order by 1,2;
    table_schema    |        table_name         
 csv_test           | yellow_taxi_trips         
 csv_test           | yellow_taxi_trips_orc     
 csv_test           | yellow_taxi_trips_staging 
 information_schema | applicable_roles          
 information_schema | columns

This should help you show tables from all schemas.