.. -*- coding: utf-8; -*-

==================
 Oracle database.
==================
.. contents::
   :local:

Oracle database development environment.
========================================

http://en.wikipedia.org/wiki/Oracle_SQL_Developer
  Integrated development environment (IDE) for working with
  SQL/PLSql in Oracle databases.
http://en.wikipedia.org/wiki/SQL*Plus
  An Oracle database client that can run SQL and PL/SQL commands
  and display their results.
http://en.wikipedia.org/wiki/Oracle_Forms
  Is a software product for creating screens that interact with an
  Oracle database. It has an IDE including an object navigator,
  property sheet and code editor that uses PL/SQL.
http://en.wikipedia.org/wiki/Oracle_JDeveloper
  JDeveloper is a freeware IDE supplied by Oracle Corporation. It
  offers features for development in Java, XML, SQL and PL/SQL,
  HTML, JavaScript, BPEL and PHP.
http://en.wikipedia.org/wiki/Oracle_Reports
  Oracle Reports is a tool for developing reports against data
  stored in an Oracle database.

Useful PL/SQL stubs
===================

Declare executable block::

  declare
  begin
    null;
  end;
  /

Using variables::

  declare
    x number;
  begin
    select 1 into x from dual;
  end;
  /

Call procedure::

  create or replace procedure MY_PROC as
  begin
    null;
  end;
  /

  begin
    MY_PROC;
  end;
  /

Call function::

  create or replace function MY_FUN return number as
  begin
    return 42;
  end;
  /

  declare
    x NUMBER;
  begin
    ret := MY_FUN();
  end;
  /

Common client options
=====================

Following options supports Sql*Plus, SQLcl, Oracle Developer.

Enabling printing::

  set serveroutput on;
  exec DBMS_OUTPUT.PUT_LINE('Hello');
  exec DBMS_OUTPUT.DISABLE();
  exec DBMS_OUTPUT.PUT_LINE('Silence');
  exec DBMS_OUTPUT.ENABLE();

Enable printing of query execution time::

  set timing on;

Sql*Plus client options
=======================

Enable printing execution plan stats::

  set autotrace on;
  set autotrace off;
  set autotrace on statistics;
  set autotrace on explain;

Disable printing of ``select`` result, show only stats::

  set autotrace traceonly;
  set autotrace traceonly on explain;

Adjust date format.
===================
::

  column parameter format a32;
  column value format a32;
  select parameter, value from v$nls_parameters;

  alter session set NLS_DATE_FORMAT = 'yyyy-mm-dd HH:MI:SS';
  alter session set NLS_TIMESTAMP_FORMAT = 'MI:SS.FF6';
  alter session set NLS_TIME_FORMAT = 'HH24:MI:SS.FF6';

  alter session set TIME_ZONE = '+06:00';

  select sysdate from dual;

Working with SQL/Plus
=====================

Show error details::

  show errors;

Modify output format::

  set pagesize 40;
  set linesize 400;

Database info
=============

List of users::

  select distinct(OWNER) from ALL_TABLES;

List of current user owned tables::

  select * from USER_TABLES;
  select TABLE_NAME from USER_TABLES;

List of tables by owner::

  select OWNER || '.' || TABLE_NAME from ALL_TABLES
    order by OWNER;

List of current user table sizes::

  select SEGMENT_NAME, SEGMENT_TYPE, sum(BYTES) from USER_EXTENTS
    group by SEGMENT_NAME, SEGMENT_TYPE order by sum(BYTES);

  select sum(BYTES) from USER_EXTENTS;

Get LOB stored size::

  select sum(dbms_lob.getchunksize(COL))/1024/1024 MiB from TBL;

Table indexes restricted to user::

  select * from USER_INDEXES order by TABLE_NAME;

Table indexes available to user::

  select * from ALL_INDEXES order by TABLE_NAME;

All table indexes::

  select * from DBA_INDEXES order by TABLE_NAME;

View index columns::

  select * from DBA_IND_COLUMNS;
  select * from ALL_IND_COLUMNS;
  select * from USER_IND_COLUMNS;

Vie index expressions::

  select * from DBA_IND_EXPRESSIONS;
  select * from ALL_IND_EXPRESSIONS;
  select * from USER_IND_EXPRESSIONS;

List of index sizes::

  select index_name, table_name, sum(user_extents.bytes) as bytes from user_indexes
    left outer join user_extents on user_extents.segment_name = table_name
    group by index_name, table_name
    order by table_name;

View index statistics::

  select * from DBA_IND_STATISTICS;
  select * from ALL_IND_STATISTICS;
  select * from USER_IND_STATISTICS;
  select * from INDEX_STATS;

List of tables without primary keys::

  select OWNER || '.' || TABLE_NAME from ALL_TABLES
    where TABLE_NAME not in (
      select distinct TABLE_NAME from ALL_CONSTRAINTS where CONSTRAINT_TYPE = 'P'
    ) and OWNER in ('USER1', 'USER2')
    order by OWNER, TABLE_NAME;

List tables that has foreign key to given table::

  select * from SYS.USER_CONSTRAINTS cons
    join SYS.USER_CONSTRAINTS rcons on rcons.CONSTRAINT_NAME = cons.R_CONSTRAINT_NAME
    where cons.CONSTRAINT_TYPE = 'R' and rcons.TABLE_NAME = 'TBL_NAME';

  select * from SYS.USER_CONSTRAINTS cons
    join SYS.USER_CONSTRAINTS rcons on rcons.CONSTRAINT_NAME = cons.R_CONSTRAINT_NAME
    where cons.CONSTRAINT_TYPE = 'R' and rcons.TABLE_NAME like '%/_OLD' escape '/';

List of missing index for foreign key constraint::

  select
    case when b.table_name is null then 'unindexed' else 'indexed' end as status,
    a.table_name      as table_name,
    a.constraint_name as fk_name,
    a.fk_columns      as fk_columns,
    b.index_name      as index_name,
    b.index_columns   as index_columns
  from (
    select
      a.table_name,
      a.constraint_name,
      listagg(a.column_name, ',') within group (order by a.position) fk_columns
    from user_cons_columns a, user_constraints b
    where
      a.constraint_name = b.constraint_name
      and b.constraint_type = 'R'
      and a.owner = b.owner
    group by a.table_name, a.constraint_name
  ) a, (
    select
      table_name,
      index_name,
      listagg(c.column_name, ',') within group (order by c.column_position) index_columns
    from user_ind_columns c
    group by table_name, index_name
  ) b
  where a.table_name = b.table_name(+)
    and b.index_columns(+) like a.fk_columns || '%'
  order by 1 desc, 2;

List of current constraints limited to current user::

  select * from USER_CONSTRAINTS;

List of constraints available to user::

  select * from ALL_CONSTRAINTS;

List of all constraints::

  select * from DBA_CONSTRAINTS;

.. note::
   ``CONSTRAINT_TYPE``:

   * ``C`` (check constraint on a table)
   * ``P`` (primary key)
   * ``U`` (unique key)
   * ``R`` (referential integrity)
   * ``V`` (with check option, on a view)
   * ``O`` (with read only, on a view)

List of tablespaces::

  select distinct TABLESPACE_NAME from USER_TABLES;

List user objects::

  select OBJECT_NAME, OBJECT_TYPE from USER_OBJECTS
    order by OBJECT_TYPE, OBJECT_NAME;

List of current user permissions::

  select * from SESSION_PRIVS;

List of user permissions to tables::

  select * from ALL_TAB_PRIVS where TABLE_SCHEMA not like '%SYS' and TABLE_SCHEMA not like 'SYS%';

List of user privileges::

  select * from USER_SYS_PRIVS
  select * from USER_TAB_PRIVS
  select * from USER_ROLE_PRIVS

List of other users that have access to given user tables::

  select * from ALL_TAB_PRIVS where GRANTOR = 'ME';

Dump how exactly field stored::

  select dump(date '2009-08-07') from dual;
  select dump(sysdate) from dual;

https://dba.stackexchange.com/questions/11047/how-to-retrieve-foreign-key-constraints-data/
  How to retrieve foreign key constraints data.

Managing data files location
============================

To find out where is data files located run as ``sysdba``::

  select * from dba_data_files;
  select * from dba_temp_files;

Above files represent table spaces::

  select * from dba_tablespaces;

Another information about installation::

  select * from v$controlfile;
  select * from v$tablespace;
  select * from v$database;
  show parameter control_files;

Place for dumps::

  show parameter user_dump_dest;

Sessions and locks
==================

List locked objects::

  select * from v$locked_object;

  select * from v$locked_object a, all_objects b
    where a.object_id = b.object_id;

  select b.owner, b.object_name, a.oracle_username, a.os_user_name
    from v$locked_object a, all_objects b
    where a.object_id = b.object_id;

  select
     c.owner,
     c.object_name,
     c.object_type,
     b.sid,
     b.serial#,
     b.status,
     b.osuser,
     b.machine
  from v$locked_object a, v$session b, dba_objects c
  where b.sid = a.session_id and a.object_id = c.object_id;

  select * from DBA_BLOCKERS;
  select * from DBA_DDL_LOCKS;
  select * from DBA_DML_LOCKS;
  select * from DBA_LOCK_INTERNAL;
  select * from DBA_LOCKS;
  select * from DBA_WAITERS;

Kill session::

  alter system kill session 'SID,SERIAL#';
  alter system kill session '361,565';

List session parameters::

  select * from v$parameter;
  select NAME, VALUE from v$parameter;

  show parameters ddl_lock_timeout;

Alter session parameter::

  alter session set ddl_lock_timeout = 10;

Installing express edition
==========================

Disable APEX port
-----------------

Find APEX port in usage::

  select dbms_xdb.GetHttpPort, dbms_xdb.GetFtpPort from dual;

Disable APEX lisener (to free useful 8080 port) from ``system``::

  execute dbms_xdb.SetHttpPort(0);

or move to another port::

  execute dbms_xdb.SetHttpPort(8090);

http://stackoverflow.com/questions/165105/how-to-disable-oracle-xe-component-which-is-listening-on-8080
  How to disable Oracle XE component which is listening on 8080?
http://daust.blogspot.co.il/2006/01/xe-changing-default-http-port.html
  XE: Changing the default http port.
https://erikwramner.wordpress.com/2014/03/23/stop-oracle-xe-from-listening-on-port-8080/
  Stop Oracle XE from listening on port 8080.

Creating user
-------------

From ``system`` account::

  create user BOB identified by 123456;
  alter user BOB account unlock;
  alter user BOB default tablespace USERS;
  alter user BOB temporary tablespace TEMP;
  alter user BOB quota 100M on USERS;
  grant CREATE SESSION, ALTER SESSION to BOB;
  grant CREATE PROCEDURE, CREATE TRIGGER to BOB;
  grant CREATE TABLE, CREATE SEQUENCE, CREATE VIEW, CREATE SYNONYM to BOB;

Profiling
=========

``explain plan for`` can be used to show probable execution plan for query::

  explain plan for select 1 from dual;

``plan_table`` should be examined to display result::

  select * from table(dbms_xplan.display);

Remove statistics::

  execute DBMS_STATS.DELETE_SCHEMA_STATS('BOB');

Collect statistics::

  execute DBMS_STATS.GATHER_DATABASE_STATS;
  execute DBMS_STATS.GATHER_SCHEMA_STATS('BOB');
  execute DBMS_STATS.GATHER_TABLE_STATS('BOB', 'EMPLOYEE');

Get actual execution plan of query after executing query::

  select * from table(dbms_xplan.display_cursor);
  select * from table(dbms_xplan.display_cursor(format => 'basic'));
  select * from table(dbms_xplan.display_cursor(format => 'typical'));
  select * from table(dbms_xplan.display_cursor(format => 'all'));

Last queries' execution stats are available through ``v$sql`` view::

  grant select on v_$sql to BOB;

  select * from v$sql;
  select * from v$sql_plan;

  select LAST_LOAD_TIME, ELAPSED_TIME, MODULE, SQL_TEXT elasped from v$sql
    order by LAST_LOAD_TIME desc

Improved version of above code::

  column LAST_LOAD_TIME format a20;
  column TIME format a20;
  column MODULE format a10;
  column SQL_TEXT format a60;

  set autotrace off;
  set timing off;

  select * from (
    select LAST_LOAD_TIME, to_char(ELAPSED_TIME/1000, '999,999,999.000') || ' ms' as TIME, MODULE, SQL_TEXT from SYS."V_\$SQL"
      where SQL_TEXT like '%BATCH_BRANCHES%'
      order by LAST_LOAD_TIME desc
    ) where ROWNUM <= 5;

In SQL/Plus query execution time (up to )::

  SET TIMING ON;
  -- do stuff
  SET TIMING OFF;

or::

  set serveroutput on;
  variable n number;
  exec :n := dbms_utility.get_time;
  select ......
  exec dbms_output.put_line( (dbms_utility.get_time-:n)/100) || ' seconds....' );

In SQL Developer you get execution time in result window. By default SQL
Developer limit output to 50 rows. To run full query select result window nat
press ``Ctrl+End``.

Alternatively you may wrap you query with (and optionally use hint to disable
optimizations??)::

  select count(*) from ( ... ORIGINAL QUERY ... );

Another option is::

  delete plan_table;
  explain plan for ... SQL statement ...;
  select time from plan_table where id = 0;

.. note::
   From docs:

     PLAN_TABLE is automatically created as a global temporary table to hold the output of an
     EXPLAIN PLAN statement for all users. PLAN_TABLE is the default sample output table into which
     the EXPLAIN PLAN statement inserts rows describing execution plans.

See:

http://docs.oracle.com/cd/B19306_01/server.102/b14237/dynviews_2113.htm
  $SQL lists statistics on shared SQL area without the GROUP BY clause.
http://stackoverflow.com/questions/22198853/finding-execution-time-of-query-using-sql-developer
  Finding Execution time of query using SQL Developer.
http://stackoverflow.com/questions/3559189/oracle-query-execution-time
  Oracle query execution time.
http://tkyte.blogspot.com/2007/04/when-explanation-doesn-sound-quite.html
   When the explanation doesn't sound quite right...

Last table modification time.
=============================
::

  select max(scn_to_timestamp(ora_rowscn)) from TBL;

  select timestamp from all_tab_modifications where table_owner = 'OWNER';
  select timestamp from all_tab_modifications where table_name = 'TABLE';

List of Oracle Reserved Words.
==============================

* http://docs.oracle.com/cd/B19306_01/em.102/b40103/app_oracle_reserved_words.htm

Find time zone
==============

Set TZ data formt::

  alter session set 'YYYY-MM-DD HH24:MI:SS.FF3 TZR';

For system TZ look to TZ in::

  select SYSTIMESTAMP from dual;

For session TZ look to TZ in::

  select CURRENT_TIMESTAMP from dual;

or directly in::

  select SESSIONTIMEZONE from dual;

You can adjust session TZ by::

  alter session set TIME_ZONE ='+06:00';

which affect on ``CURRENT_DATE``, ``CURRENT_TIMESTAMP``, ``LOCALTIMESTAMP``.

``DBTIMEZONE`` is set when database is created and can't be altered if the
database contains a table with a ``TIMESTAMP WITH LOCAL TIME ZONE`` column and
the column contains data::

  select DBTIMEZONE from dual;

Find time at timezone::

  select SYSTIMESTAMP at time zone 'GMT' from dual;

Move data across DBes
=====================

Format ``select`` data as ``insert`` statements with ``/*insert*/`` hind (use ``F5`` key in Oracle
developer)::

  select /*insert*/ * from tbl;

Another useful hint::

  select /*csv*/ * from tbl;

Alternatively enable output as ``insert`` statments (use ``F5`` key in Oracle developer)::

  set sqlformat insert;
  select * from tbl;

  spool /home/user/insert.sql;
  select * from tbl where ...;
  spool off;

Another ``sqlformat``::

  set sqlformat default;
  set sqlformat csv;
  set sqlformat html;
  set sqlformat xml;
  set sqlformat json;

https://dba.stackexchange.com/questions/173540/generate-insert-statements-for-each-entry-in-a-table
  Generate ``insert`` statements for each entry in a table.
https://oracle-base.com/articles/misc/sqlcl-format-query-results-with-the-set-sqlformat-command
  SQLcl : Format Query Results with the SET SQLFORMAT Command.

Unlock expired password
=======================

Login as sysdba::

  sqlplus / as sysdba

Check expiration date for user::

  select EXPIRY_DATE from DBA_USERS where USERNAME = 'me';
  select USERNAME, ACCOUNT_STATUS from DBA_USERS where USERNAME = 'me';

Connect as sysdba to the database and reset password and unlock user::

  alter user <USER> identified by <PASSWORD>;
  alter user <USER> account unlock;

or with single request::

  alter user <USER> identified by <PASSWORD> account unlock;

To make password lasts infinitely check which profile is used assigned::

  select USERNAME, PROFILE from DBA_USERS;

and check settings for this profile::

  select * from DBA_PROFILES where PROFILE = 'SA';

and reset limits for password lifetime::

  alter profile DEFAULT limit PASSWORD_LIFE_TIME UNLIMITED;

You may create separate profile with its own settings::

  create profile MY;
  alter profile MY PASSWORD_LIFE_TIME UNLIMITED;
  alter user <USER> profile MY;

To completely disable all password checks::

  alter profile DEFAULT limit COMPOSITE_LIMIT UNLIMITED
    PASSWORD_LIFE_TIME UNLIMITED
    PASSWORD_REUSE_TIME UNLIMITED
    PASSWORD_REUSE_MAX UNLIMITED
    PASSWORD_VERIFY_FUNCTION NULL
    PASSWORD_LOCK_TIME UNLIMITED
    PASSWORD_GRACE_TIME UNLIMITED
    FAILED_LOGIN_ATTEMPTS UNLIMITED;

Oracle naming conventions
=========================

http://www.gplivna.eu/papers/naming_conventions.htm
https://oracle-base.com/articles/misc/naming-conventions