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Teradata RDBMS Database Administration - NCR

NCR Teradata RDBMS Database Administration - NCR , 2004. - 616 p.
Download (direct link): teradatadatabaseadmin2004.pdf
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4 We lock a distinct DBC."pseudo table" for write on a RowHash to prevent global deadlock for DBC.Parents.

5 We lock a distinct DBC."pseudo table" for write on a RowHash to prevent global deadlock for DBC.Owners.

6 We lock DBC.DataBaseSpace for write, we lock DBC.AccessRights for write, we lock DBC.DBase for write on a RowHash, we lock DBC.DBase for write on a RowHash, we lock DBC.Accounts for write on a RowHash, we lock DBC.Parents for write, and we lock DBC.Owners for write.

7 We execute the following steps in parallel.

We do a single-AMP ABORT test from DBC.DBase by way of the unique primary index with no residual conditions.

We do a single-AMP ABORT test from DBC.DBase by way of the unique primary index.

We do a single-AMP ABORT test from DBC.DBase by way of the unique primary index.

We do an INSERT into DBC.DBase.

We do a single-AMP UPDATE from DBC.DBase by way of the unique primary index with no residual conditions.

We do a single-AMP RETRIEVE step from DBC.Parents by way of the primary index with no residual conditions into Spool 1, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 1 by row hash.

Note: Several steps are performed in parallel during the CREATE USER statement.

8 We do a MERGE into DBC.Owners from Spool 1 (Last Use).

9 We execute the following steps in parallel.

10 We do an INSERT into DBC.Owners.

11 We do a single-AMP RETRIEVE step from DBC.Parents by way of the primary index with no residual conditions into Spool 2, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 2 by row hash.

12 We do a MERGE into DBC.Parents from Spool 2 (Last Use).

13 We execute the following steps in parallel.

We do an INSERT into DBC.Parents.

We do an INSERT into DBC.Accounts.

5 - 32 Teradata RDBMS Database Administration

Chapter 5: Setting Up Users, Profiles, Accounts and Accounting

Using the Data Dictionary Views

We do a single-AMP RETRIEVE step from DBC.AccessRights by way of the primary index into Spool 3, which is redistributed by hash code to all AMPs.

14 We execute the following steps in parallel.

We do a single-AMP RETRIEVE step from DBC.AccessRights by way of the primary index into Spool 3, which is redistributed by hash code to all AMPs.

We do an all-AMPs RETRIEVE step from DBC.AccessRights by way of an all-rows scan into Spool 4, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 4 by row hash.

15 We do an all-AMPs JOIN step from DBC.Owners by way of a RowHash match scan, which is joined to Spool 4 (Last Use). DBC.Owners and Spool 4 are joined using a merge join. The result goes into Spool 3, which is redistributed by hash code to all AMPs. Then we do a SORT to order Spool 3 by row hash.

16 We do a MERGE into DBC.AccessRights from Spool 3 (Last Use).

17 We flush the DISKSPACE and AMPUSAGE caches.

18 We do an all-AMPs ABORT test from DBC.DataBaseSpace by way of the unique primary index.

19 We do an INSERT into DBC.DataBaseSpace.

20 We do an all-AMPs UPDATE from DBC.DataBaseSpace by way of the unique primary index with no residual conditions.

21 We flush the DISKSPACE and AMPUSAGE caches.

22 We spoil the parser's dictionary cache for the database.

23 Finally, we send out an END TRANSACTION step to all AMPs involved in processing the request.

Note: No rows are returned to the user as the result of statement

5 - 32

Teradata RDBMS Database Administration Chapter 5: Setting Up Users, Profiles, Accounts and Accounting

System Accounting Functions

System Accounting Views

Teradata RDBMS provides the following views to support administration of accounts and accounting functions:

DBC.AccountInfo

DBC.AMPUsage

DBC.AccountInfo

The DBC.AccountInfo view accesses the DBC.Dbase, DBC.Profiles, and DBC.Accounts dictionary tables to return information about all valid accounts for all databases, users, and profiles.

Use DBC.AccountInfo to find out:

What accounts are valid for which user

The assignment of:

Priority Scheduling codes

ASE codes

This dictionary table . Stores .
DBC.Accounts all accounts for all databases, users, and profiles. If an account is not specified at creation time, the default is used. The default is determined as explained in "Finding the Default Account" on page 5-21. DBC.Accounts is used to verify any account entered by a user at logon time or with a SET SESSION ACCOUNT statement.
DBC.DBase the default account for each: Database User If a database or user is defined with multiple accounts, the first is used as the default. If a user is assigned a profile that is defined with one or more accounts, the first profile account is used as the default. (All profile accounts take precedence over any user account.)
DBC.Profiles the default account for each profile. If multiple accounts are defined, the first is used. Note: If an account is not specified for a profile, the value is NULL in the DefaultAccounts field for that profile.
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