1.17 Workspace Managerを使用した簡単な例

このトピックでは、Workspace Managerを使用していくつかの使用例を試行し、その1つを選択するための簡単な例を2つ示します。

それぞれの例では、複数の作業領域と1つ以上のセーブポイントを使用します。一方の例(例: 倉庫拡張のオプション)では、Oracleサンプル・スキーマ内のOE.WAREHOUSES表を使用します。

どちらの例でも、この章で説明した概念を示し、「DBMS_WMパッケージ: リファレンス」に示すプロシージャを使用します。

• 例: マーケティング予算のオプション
  
• 例: 倉庫拡張のオプション
  

1.17.1 例: マーケティング予算のオプション

例1-4では、ある清涼飲料(コーラ)メーカーが4つの製品を製造し、その製品ごとにマーケティング・マネージャを配置し、マーケティング予算を計上している例を示します。1つの製品(cola_b)が市場で非常に大幅な成長が見込まれるため、この企業は、異なるマネージャや予算額を想定したwhat-if 分析を行っています。

例1-4 マーケティング予算のオプション

-------------------------------------------------------------------
-- INITIAL SET-UP
-------------------------------------------------------------------
-- Create the user for schema objects.
CREATE USER wm_developer IDENTIFIED BY password;

-- Grant regular privileges.
GRANT create session, 
  unlimited tablespace, 
  create table
TO wm_developer;

-- Grant WM-specific privileges (with grant_option = YES).
EXECUTE DBMS_WM.GrantSystemPriv ('ACCESS_ANY_WORKSPACE, MERGE_ANY_WORKSPACE,
 CREATE_ANY_WORKSPACE, REMOVE_ANY_WORKSPACE, ROLLBACK_ANY_WORKSPACE',
 'wm_developer', 'YES');

---------------------------------------------------------------------------
-- CREATE AND POPULATE DATA TABLE --
---------------------------------------------------------------------------
CONNECT wm_developer
-- Enter password when prompted.

-- Cleanup: remove B_focus_2 workspace if it exists from previous run.
EXECUTE DBMS_WM.RemoveWorkspace ('B_focus_2');

-- Create a table for the annual marketing budget for
-- several cola (soft drink) products.
-- Each row will contain budget data for a specific
-- product. Note: This table does not reflect recommended
-- database design. (For example, a manager ID should
-- be used, not a name.) It is deliberately oversimplified
-- for purposes of illustration.

CREATE TABLE cola_marketing_budget (
  product_id NUMBER PRIMARY KEY,
  product_name VARCHAR2(32),
  manager VARCHAR2(32),  -- Here a name, just for simplicity
  budget NUMBER  -- Budget in millions of dollars. Example: 3 = $3,000,000.
);

-- Version-enable the table. Specify hist option of VIEW_WO_OVERWRITE so that
-- the COLA_MARKETING_BUDGET_HIST view contains complete history information
-- about data changes.
EXECUTE DBMS_WM.EnableVersioning ('cola_marketing_budget', 'VIEW_WO_OVERWRITE');

INSERT INTO cola_marketing_budget VALUES(
  1,
  'cola_a',
  'Alvarez',
  2.0
);
INSERT INTO cola_marketing_budget VALUES(
  2,
  'cola_b',
  'Baker',
  1.5
);
INSERT INTO cola_marketing_budget VALUES(
  3,
  'cola_c',
  'Chen',
  1.5
);
INSERT INTO cola_marketing_budget VALUES(
  4,
  'cola_d',
  'Davis',
  3.5
);
COMMIT;

-- Relevant data values now in LIVE workspace:
-- 1, cola_a, Alvarez, 2.0
-- 2, cola_b, Baker, 1.5
-- 3, cola_c, Chen, 1.5
-- 4, cola_d, Davis, 3.5

---------------------------------------------------------------------------
-- CREATE WORKSPACES --
---------------------------------------------------------------------------
-- Create workspaces for the following scenario: a major marketing focus
-- for the cola_b product. Managers and budget amounts for each
-- product can change, but the total marketing budget cannot grow.
--
-- One scenario (B_focus_1) features a manager with more expensive 
-- plans (which means more money taken from other products' budgets).
-- The other scenario (B_focus_2) features a manager with less expensive 
-- plans (which means less money taken from other products' budgets).
--
-- Two workspaces (B_focus_1 and B_focus_2) are created as child workspaces 
-- of the LIVE database workspace.

EXECUTE DBMS_WM.CreateWorkspace ('B_focus_1');
EXECUTE DBMS_WM.CreateWorkspace ('B_focus_2');

---------------------------------------------------------------------------
-- WORK IN FIRST WORKSPACE --
---------------------------------------------------------------------------
-- Enter the B_focus_1 workspace and change the cola_b manager to Beasley and 
-- raise the cola_b budget amount by 1.5 to bring it to 3.0. Reduce all other 
-- products' budget amounts by 0.5 to stay within the overall budget.

EXECUTE DBMS_WM.GotoWorkspace ('B_focus_1');
UPDATE cola_marketing_budget
  SET manager = 'Beasley' WHERE product_name = 'cola_b';
UPDATE cola_marketing_budget
  SET budget = 3 WHERE product_name = 'cola_b';
UPDATE cola_marketing_budget
  SET budget = 1.5 WHERE product_name = 'cola_a';
UPDATE cola_marketing_budget
  SET budget = 1 WHERE product_name = 'cola_c';
UPDATE cola_marketing_budget
  SET budget = 3 WHERE product_name = 'cola_d';
COMMIT;

-- Relevant data values now in B_focus_1 workspace::
-- 1, cola_a, Alvarez, 1.5
-- 2, cola_b, Beasley, 3.0
-- 3, cola_c, Chen, 1.0
-- 4, cola_d, Davis, 3.0

-- Freeze this workspace to prevent any changes until workspace is unfrozen.
-- However, first go to the LIVE workspace, because a workspace cannot be frozen
-- if any users (including you) are in it.
EXECUTE DBMS_WM.GotoWorkspace ('LIVE');
EXECUTE DBMS_WM.FreezeWorkspace ('B_focus_1');

---------------------------------------------------------------------------
-- CREATE ANOTHER SCENARIO IN SECOND WORKSPACE --
---------------------------------------------------------------------------
-- Enter the B_focus_2 workspace and change the cola_b manager to Burton and 
-- raise the cola_b budget amount by 0.5 to bring it to 2.0. Reduce only the 
-- cola_d amount by 0.5 to stay within the overall budget.

EXECUTE DBMS_WM.GotoWorkspace ('B_focus_2');
UPDATE cola_marketing_budget
  SET manager = 'Burton' WHERE product_name = 'cola_b';
UPDATE cola_marketing_budget
  SET budget = 2 WHERE product_name = 'cola_b';
UPDATE cola_marketing_budget
  SET budget = 3 WHERE product_name = 'cola_d';
COMMIT;

-- Relevant data values now in B_focus_2 workspace::
-- 1, cola_a, Alvarez, 2.0 (no change from LIVE)
-- 2, cola_b, Burton, 2.0
-- 3, cola_c, Chen, 1.5 (no change from LIVE)
-- 4, cola_d, Davis, 3.0 (same manager, new budget)

-- Create a savepoint (B_focus_2_SP1), then change scenario to 
-- raise cola_b budget and reduce cola_d budget by 0.5 each.

EXECUTE DBMS_WM.CreateSavepoint ('B_focus_2', 'B_focus_2_SP1');
UPDATE cola_marketing_budget
  SET budget = 2.5 WHERE product_name = 'cola_b';
UPDATE cola_marketing_budget
  SET budget = 2.5 WHERE product_name = 'cola_d';
COMMIT;

-- Relevant data values now in B_focus_2 workspace:
-- 1, cola_a, Alvarez, 2.0 (no change from LIVE)
-- 2, cola_b, Burton, 2.5 
-- 3, cola_c, Chen, 1.5 (no change from LIVE)
-- 4, cola_d, Davis, 2.5 (same manager, new budget)

-- Discard this scenario; roll back to row values at the time savepoint 
-- B_focus_2_SP1 was created. First, though, get out of the workspace
-- so it can be rolled back (no users in it).

EXECUTE DBMS_WM.GotoWorkspace ('LIVE');
EXECUTE DBMS_WM.RollbackToSP ('B_focus_2', 'B_focus_2_SP1');

-- Go back to the B_focus_2 workspace and display current values 
-- (should include budget of 2 for cola_b and 3 for cola_d).
EXECUTE DBMS_WM.GotoWorkspace ('B_focus_2');
SELECT * FROM cola_marketing_budget;

---------------------------------------------------------------------------
-- SELECT SCENARIO AND UPDATE DATABASE --
---------------------------------------------------------------------------
-- Assume that you have decided to adopt the scenario of the second 
-- workspace (B_focus_2) using that workspace's current values.

-- First go to the LIVE workspace, because a workspace cannot be removed
-- or merged if any users (including you) are in it.
EXECUTE DBMS_WM.GotoWorkspace ('LIVE');

-- Unfreeze the first workspace and remove it to discard any changes there.
EXECUTE DBMS_WM.UnfreezeWorkspace ('B_focus_1');
EXECUTE DBMS_WM.RemoveWorkspace ('B_focus_1');

-- Apply changes in the second workspace to the LIVE database workspace.
-- Note that the workspace is not removed by default after MergeWorkspace.
EXECUTE DBMS_WM.MergeWorkspace ('B_focus_2');

-- Display the current data values as seen by the LIVE workspace.
SELECT * FROM cola_marketing_budget;

---------------------------------------------------------------------------
-- DISABLE VERSIONING --
---------------------------------------------------------------------------
-- Disable versioning on the table because you are finished testing scenarios.
-- Set force parameter to TRUE if you want to force the disabling even
-- if changes were made in a non-LIVE workspace.

EXECUTE DBMS_WM.DisableVersioning ('cola_marketing_budget', TRUE);

1.17.2 例: 倉庫拡張のオプション

例1-5では、Oracleサンプル・スキーマを使用する企業で倉庫スペースの増設が必要であることが決定されています。この会社は2つの使用例を検討しようとしています。一方はTown Aに大規模倉庫を1つ建設する案、他方はTown BとTown Cに小規模倉庫を2つ建設して全体の保管能力を拡大する案です。どちらの使用例にも潜在的なメリットとデメリットがあり、それぞれに解決する必要のある財務上および法律上の課題があります。その後、この会社はそれぞれの使用例で倉庫スペースのさらなる増設が必要となる可能性があると判断したため、両方の使用例に同じ倉庫を追加する案を検討しようとしています。

例1-5では、使用例ごとに作業領域を1つ作成し、各作業領域内にセーブポイントを作成してから、新規倉庫を表に追加しています。これは、この会社が追加の倉庫を使用しないと判断する可能性があるためです。倉庫の行は、Oracleサンプル・スキーマの一部であるOE.WAREHOUSES表に格納されています。

例1-5 倉庫拡張のオプション

-------------------------------------------------------------------
-- INITIAL SET-UP
-------------------------------------------------------------------
-- Clean up from any previous running of this procedure.
DROP USER wm_developer CASCADE;

-- Create the user for schema objects.
CREATE USER wm_developer IDENTIFIED BY password;

-- Grant regular privileges.
GRANT create session, 
  unlimited tablespace,
  create table
TO wm_developer;

-- Grant privileges on tables to be modified.
GRANT select, insert, delete, update ON oe.warehouses TO wm_developer; 
GRANT select, insert, delete, update ON hr.locations TO wm_developer; 

-- Grant WM-specific privileges (with grant_option = YES).
EXECUTE DBMS_WM.GrantSystemPriv ('ACCESS_ANY_WORKSPACE, MERGE_ANY_WORKSPACE,
 CREATE_ANY_WORKSPACE, REMOVE_ANY_WORKSPACE, ROLLBACK_ANY_WORKSPACE',  
 'wm_developer', 'YES');

-- WM_ADMIN_ROLE grants the ability to version-enable a table in another schema.
GRANT wm_admin_role TO wm_developer;

-- Create rows for new locations, since a valid location ID is needed for each
-- proposed new warehouse.
INSERT INTO hr.locations VALUES 
   (4000, '123 Any Street', '01234', 'Town A', 'MA', 'US');
INSERT INTO hr.locations VALUES 
   (4100, '456 Some Street', '01235', 'Town B', 'MA', 'US');
INSERT INTO hr.locations VALUES 
   (4200, '789 Other Street', '01236', 'Town C', 'MA', 'US');
INSERT INTO hr.locations VALUES 
   (4300, '1 Yetanother Street', '01237', 'Town D', 'MA', 'US');

---------------------------------------------------------------------------
-- CREATE AND VERSION-ENABLE THE DATA TABLE --
---------------------------------------------------------------------------
CONNECT wm_developer
-- Enter password when prompted.
set echo on
set serveroutput on

-- Version-enable the OE.WAREHOUSES table. Specify hist option of 
-- VIEW_WO_OVERWRITE so that the WAREHOUSES_HIST view contains 
-- complete history information about data changes. However, because 
-- OE.WAREHOUSES is the parent table in a referential integrity constraint
-- with OE.INVENTORIES, you must also version-enable that table.

EXECUTE DBMS_WM.EnableVersioning ('OE.WAREHOUSES, OE.INVENTORIES', hist => 'VIEW_WO_OVERWRITE');

------------------------------------------------------------------------
-- CREATE AND USE WORKSPACES --
------------------------------------------------------------------------
-- The company has decided that it needs additional warehouse space. 
-- It wants to consider two scenarios: a single large warehouse in Town A,
-- and two smaller warehouses in Town B and Town C that together offer more
-- total storage capacity. There are potential advantages and disadvantages 
-- to each scenario, and financial and legal issues to be resolved with each.
--
-- Later, the company decides that it might need even more warehouse
-- space under each scenario, so it wants to consider the same additional 
-- warehouse in each scenario.

-- Create a workspace for each scenario, with both created as child 
-- workspaces of the LIVE database workspace.
-- In workspace large_warehouse, add one row for the single large warehouse.
-- In workspace smaller_warehouses, add two rows, one for each warehouse.
--
-- Also, within each workspace create a savepoint before adding the
-- extra warehouse, because the company might decide it does not
-- need the warehouse.

EXECUTE DBMS_WM.CreateWorkspace (workspace => 'large_warehouse');
EXECUTE DBMS_WM.CreateWorkspace (workspace => 'smaller_warehouses');

-- Set up the first scenario: Go to the large_warehouse workspace and first add
-- one row for a warehouse.

EXECUTE DBMS_WM.GotoWorkspace (workspace => 'large_warehouse');

INSERT INTO oe.warehouses VALUES (10, NULL, 'Town A', 4000,
  SDO_GEOMETRY(2001, 8307, 
  SDO_POINT_TYPE(-71.00703, 42.27099, NULL), NULL, NULL)); 

UPDATE oe.warehouses SET warehouse_spec = sys.xmltype.createxml( 
'<?xml version="1.0"?> 
<Warehouse> 
<Building>Owned</Building> 
<Area>100000</Area> 
<Docks>2</Docks> 
<DockType>Side load</DockType> 
<WaterAccess>Y</WaterAccess> 
<RailAccess>Y</RailAccess> 
<Parking>Lot</Parking> 
<VClearance>15 ft</VClearance> 
</Warehouse>' 
) WHERE warehouse_id = 10; 

COMMIT;

-- Create a savepoint so that you can, if necessary, roll back to the point
-- before the extra warehouse was added.
EXECUTE DBMS_WM.CreateSavepoint ('large_warehouse', 'large_warehouse_add_wh');

-- Add another warehouse for this scenario.
INSERT INTO oe.warehouses VALUES (11, NULL, 'Town D', 4300,
  SDO_GEOMETRY(2001, 8307, 
  SDO_POINT_TYPE(-71.00707, 42.35226, NULL), NULL, NULL)); 

UPDATE oe.warehouses SET warehouse_spec = sys.xmltype.createxml( 
'<?xml version="1.0"?> 
<Warehouse> 
<Building>Leased</Building> 
<Area>55000</Area> 
<Docks>1</Docks> 
<DockType>Rear load</DockType> 
<WaterAccess>N</WaterAccess> 
<RailAccess>N</RailAccess> 
<Parking>Street</Parking> 
<VClearance>10 ft</VClearance> 
</Warehouse>' 
) WHERE warehouse_id = 11; 

COMMIT;

-- Freeze this workspace to prevent any changes until the workspace is unfrozen.
-- However, first go to the LIVE workspace, because a workspace cannot be frozen
-- if any users (including you) are in it.
EXECUTE DBMS_WM.GotoWorkspace ('LIVE');
EXECUTE DBMS_WM.FreezeWorkspace ('large_warehouse');

-- Set up the second scenario: Go to the smaller_warehouses workspace and first 
-- add two rows for the smaller warehouses.

EXECUTE DBMS_WM.GotoWorkspace ('smaller_warehouses');

INSERT INTO oe.warehouses VALUES (10, NULL, 'Town B', 4100,
  SDO_GEOMETRY(2001, 8307, 
  SDO_POINT_TYPE(-71.02439, 42.28628, NULL), NULL, NULL)); 

INSERT INTO oe.warehouses VALUES (11, NULL, 'Town C', 4200,
  SDO_GEOMETRY(2001, 8307, 
  SDO_POINT_TYPE(-70.97980, 42.37961, NULL), NULL, NULL)); 

UPDATE oe.warehouses SET warehouse_spec = sys.xmltype.createxml( 
'<?xml version="1.0"?> 
<Warehouse> 
<Building>Owned</Building> 
<Area>60000</Area> 
<Docks>1</Docks> 
<DockType>Side load</DockType> 
<WaterAccess>Y</WaterAccess> 
<RailAccess>Y</RailAccess> 
<Parking>Lot</Parking> 
<VClearance>15 ft</VClearance> 
</Warehouse>' 
) WHERE warehouse_id = 10; 

UPDATE oe.warehouses SET warehouse_spec = sys.xmltype.createxml( 
'<?xml version="1.0"?> 
<Warehouse> 
<Building>Leased</Building> 
<Area>550000</Area> 
<Docks>1</Docks> 
<DockType>Rear load</DockType> 
<WaterAccess>N</WaterAccess> 
<RailAccess>Y</RailAccess> 
<Parking>Street</Parking> 
<VClearance>12 ft</VClearance> 
</Warehouse>' 
) WHERE warehouse_id = 11; 

COMMIT;

-- Create a savepoint so that you can, if necessary, roll back to the point
-- before the extra warehouse was added.
EXECUTE DBMS_WM.CreateSavepoint ('smaller_warehouses', 'smaller_warehouses_add_wh');

-- Add the extra warehouse for this scenario.
INSERT INTO oe.warehouses VALUES (12, NULL, 'Town D', 4300,
  SDO_GEOMETRY(2001, 8307, 
  SDO_POINT_TYPE(-71.00707, 42.35226, NULL), NULL, NULL)); 

UPDATE oe.warehouses SET warehouse_spec = sys.xmltype.createxml( 
'<?xml version="1.0"?> 
<Warehouse> 
<Building>Leased</Building> 
<Area>55000</Area> 
<Docks>1</Docks> 
<DockType>Rear load</DockType> 
<WaterAccess>N</WaterAccess> 
<RailAccess>N</RailAccess> 
<Parking>Street</Parking> 
<VClearance>10 ft</VClearance> 
</Warehouse>' 
) WHERE warehouse_id = 12; 

COMMIT;

---------------------------------------------------------------------------
-- SELECT A SCENARIO, AND APPLY IT --
---------------------------------------------------------------------------
-- Later, the company makes its decisions:
-- 1. Add two smaller warehouses.
-- 2. Do not add the extra warehouse (that is, no third new warehouse).
-- Consequently, you need to discard the first scenario (large_warehouse
-- workspace) completely, discard the warehouse addition in the second
-- scenario (roll back to smaller_warehouses_add_wh savepoint), and 
-- apply the second scenario.

-- First go to the LIVE workspace, because a workspace cannot be removed
-- or merged if any users (including you) are in it.
EXECUTE DBMS_WM.GotoWorkspace ('LIVE');

-- Unfreeze the first workspace and remove it to discard any changes there.
EXECUTE DBMS_WM.UnfreezeWorkspace ('large_warehouse');
EXECUTE DBMS_WM.RemoveWorkspace ('large_warehouse');

-- Rollback the workspace for the second scenario to the savepoint created
-- before the extra warehouse was added.
EXECUTE DBMS_WM.RollbackToSP ('smaller_warehouses', 'smaller_warehouses_add_wh');

-- Apply changes in the smaller_warehouses workspace to the LIVE database 
-- workspace; use the remove_workspace parameter to remove the 
-- smaller_warehouses workspace after the merge.
EXECUTE DBMS_WM.MergeWorkspace ('smaller_warehouses', remove_workspace => TRUE);

-- The OE.WAREHOUSES table now has the desired data (two additional warehouses
-- from the smaller_warehouses scenario). Display the IDs and names just to be
-- sure.
SELECT warehouse_id, warehouse_name FROM oe.warehouses 
   ORDER BY warehouse_id;

-- Disable versioning on the table because you are finished testing scenarios.
-- Set the force parameter to TRUE to force disabling even though changes 
-- were made in a non-LIVE workspace. You must also version-disable
-- the other tables previously version-enabled (along with OE.WAREHOUSES).

EXECUTE DBMS_WM.DisableVersioning ('OE.WAREHOUSES, OE.INVENTORIES', force => TRUE);

-- Clean up by deleting the rows that were added to the OE.WAREHOUSES table.
DELETE FROM oe.warehouses WHERE warehouse_id >= 10;

-- Clean up by deleting the locations that were added.
DELETE FROM hr.locations WHERE location_id >= 4000;

例1-5の終わり近くにあるSELECT文は、次の例に示すように、Town BとTown Cに新しく追加された倉庫を含め、OE.WAREHOUSES表にある倉庫のIDと名前を表示します。

SELECT warehouse_id, warehouse_name FROM oe.warehouses 
   ORDER BY warehouse_id;

WAREHOUSE_ID WAREHOUSE_NAME                                                     
------------ -----------------------------------                                
           1 Southlake, Texas                                                   
           2 San Francisco                                                      
           3 New Jersey                                                         
           4 Seattle, Washington                                                
           5 Toronto                                                            
           6 Sydney                                                             
           7 Mexico City                                                        
           8 Beijing                                                            
           9 Bombay                                                             
          10 Town B                                                             
          11 Town C