The total number of these views depends on the Oracle version, but is in a 1000 range. The main built-in views accessing Oracle RDBMS data dictionary tables are few, and are as follows:
ALL_PROCEDURES – lists all functions and procedures that are accessible to the current user;
ALL_SOURCE – describes the text source of the stored objects accessible to the current user;
ALL_TRIGGERS – list all the triggers accessible to the current user.
In addition there are equivalent views prefixed "USER_" which show only the objects owned by the current user and prefixed "DBA_" which show all objects in the database. Naturally the access to "DBA_" metadata views requires specific privileges.
Example 1: finding tables
Find all Tables that have PATTERN in the table name SELECT Owner AS Schema_Name, Table_Name FROM All_Tables WHERE Table_Name LIKE '%PATTERN%' ORDER BY Owner, Table_Name;
Example 2: finding columns
Find all tables that have at least one column that matches a specific PATTERN in the column name SELECT Owner AS Schema_Name, Table_Name, Column_Name FROM All_Tab_Columns WHERE Column_Name LIKE '%PATTERN%' ORDER BY 1,2,3;
Example 3: counting rows of columns
Estimate a total number of rows in all tables containing a column name that matches PATTERN COLUMN DUMMY NOPRINT COMPUTE SUM OF NUM_ROWS ON DUMMY BREAK ON DUMMY SELECT NULL DUMMY, T.TABLE_NAME, C.COLUMN_NAME, T.NUM_ROWS FROM ALL_TABLES T, ALL_TAB_COLUMNS C WHERE T.TABLE_NAME = C.TABLE_NAME AND C.COLUMN_NAME LIKE '%PATTERN%' AND T.OWNER = C.OWNER ORDER BY T.TABLE_NAME;
Note that NUM_ROWS records the number of rows which were in a table when it was last analyzed. This will most likely deviate from the actual number of rows currently in the table.
Find view columns SELECT TABLE_NAME, column_name, decode', 'NUMBER', DECODE), c.DATA_TYPE) data_type FROM cols c, obj o WHERE c.TABLE_NAME = o.object_name AND o.object_type = 'VIEW' AND c.table_name LIKE '%PATTERN%' ORDER BY c.table_name, c.column_id;
Warning: This is incomplete with respect to multiple datatypes including char, varchar and timestamp and uses extremely old, deprecated dictionary views, back to oracle 5.
Use of underscore in table and column names
The underscore is a special SQLpattern match to a single character and should be escaped if you are in fact looking for an underscore character in the LIKE clause of a query. Just add the following after a LIKE statement: ESCAPE '_' And then each literal underscore should be a double underscore: __ Example LIKE '%__G' ESCAPE '_'
