1 Chapters 19 and 20  Ch. 19: By What Authority? Users Roles Grant and revoke Synonyms  Ch. 20: Changing the Oracle Surroundings Indexes Clusters Sequences Tablespaces

2 Ch. 19: CREATE USER  CREATE USER Create user username identified by password ; Create user username identified externally;  Changing passwords Alter user username identified by password ;  Password Management – determined by DBA created profiles. Password lifetime Grace period Account lock rules Password reuse rules  Moving to another user, connect sqlplus command CONNECT CONNECT username CONNECT username / password

3 Ch. 19: CREATE ROLE  Roles manage sets of privileges.  CREATE ROLE Create role rolename ;  Standard Oracle Roles CONNECT – connect to database and perform very limited functions. RESOURCE – for basic users. DBA – all system privileges.  Maximum roles allowed is set at startup, max_enabled_roles parameter (30 on phoenix).  Roles can have passwords, but do not by default.

4 Ch. 19: GRANT and REVOKE  Grant for object privileges GRANT {privilege, … | ALL} [ (column,…) ] on object to {user | role} [with grant option] [with hierarchy option];  Grant for system privileges GRANT {system privilege | role | ALL} to {user | role} [, {user | role}, …] [identified by password] [with admin option];  Revoke takes privileges from roles or users. REVOKE {system privilege | role | ALL} [, {system privilege | role | ALL} …] from {user | role} [, {user | role}, …];

5 Ch. 19: Synonyms, Examples, Other  What you can grant to other users Tables: alter, references, index, on commit refresh, query rewrite, all PL/SQL Procedures and Functions: execute Sequences: select, alter  Synonyms provide for another name for an object. CREATE [PUBLIC] SYNONYM SYNONYM FOR  Examples: CREATE ROLE MYTEAM; GRANT MYTEAM TO JOE, TOM, SUE; GRANT SELECT ON MYTABLE TO MYTEAM; GRANT UPDATE (COL1) ON MYTABLE TO MYTEAM; CREATE PUBLIC SYNONYM TAB1 FOR MYSCHEMA.MYTABLE;  Advanced Options for Security by User Virtual private database (VPD) adds a where clause to all commands issued by the user to restrict data to only his view of the database. Oracle Label Security uses security labels on all rows, users only have access to those in their hierarchy.

6 Ch. 20: CREATE INDEX  Indexes: Contains values of data from a table and their location Pro: Used to speed data retrieval, also can enforce uniqueness. Con: Slows updates and deletes. When to use: if columns are typically used in where clause searches Primary keys and unique constraints create a unique index automatically. NULL values are not indexed.  Syntax: CREATE [BITMAP|UNIQUE] INDEX index ON table(COL1 [, COL2…] ) [REVERSE];  Other Oracle Index Features: Reverse indexes builds an index on the indexed column in reverse byte order thus increasing the dispersal of values. Bitmap indexes, new in 8 or 8i ?, associates a bitmap to values and only stores the bitmap in the index. Use with low cardinality values (e.g. T/F) Function based indexes, new in 8i. Normal indexes are not used if a function is used on the where clause column that you’re searching on.

7 Ch. 20: CREATE CLUSTER  Clusters: Stores different tables physically together. The cluster key is the column that the data would normally be joined together with.  Syntax Example: Create cluster BOOKandAUTHOR(col1 varchar2(1000)); Create table BOOKSHELF (title varchar2(100) primary key, … ) cluster BOOKandAUTHOR(title);

8 Ch. 20: CREATE SEQUENCE  Sequences: Creates a unique sequentially valued number. Used during insert and update commands usually. Typically used to create a primary key. NextVal and CurrVal get the next/current value of the sequence.  Syntax: Create sequence myseq increment by 1 start with 1; Insert into CUSTOMER (id, name) values (myseq.nextval, ‘a’); Update OTHERTABLE set id = myseq.currval;

9 Ch. 20: Tablespaces and terminology  Tablespace Tablespaces are a logical organization of space. Tablespaces owns the database’s datafiles. Database objects are stored within tablespaces.  Database: a logical collection of shared data stored in tablespaces.  File: A physical datafile belonging to a single tablespace.  Segment: A set of one or more extents that contains all the data for a specific structure within a tablespace.  Extent: A set of contiguous data blocks with in a database that make up a segment.  Block: One or more physical file blocks allocated from an existing datafile.

10  Entity-Relationship Diagram showing: Database Tablespace Extents Segments Files Blocks Ch. 20: ERD

11 Ch. 20: Tablespace clause syntax  Tablespace Clause: indicates Tablespace and other storage options for tables, indexes, constraints.  Storage Clause: indicates how extents are managed, overrides the default storage parameters of tablespace.  Syntax: CREATE TABLE tablename ( column_atype NOT NULL, column_btype,...) STORAGE ( INITIAL 100K NEXT 20K MINEXTENTS 1 MAXEXTENTS 99 PCTINCREASE 50 ) TABLESPACE USER_DATA PCTFREE 5 PCTUSED 30;

12 Ch. 20: Tablespace and Segment Example SQL> select file_name, tablespace_name, bytes, blocks from dba_data_files FILE_NAME TABLESPACE_NAME BYTES BLOCKS /opt/oracle/u1/oradata/OS80/users01.dbf USERS /opt/oracle/u1/oradata/OS80/tools01.dbf TOOLS /opt/oracle/u1/oradata/OS80/temp01.dbf TEMP /opt/oracle/u1/oradata/OS80/rbs01.dbf RBS /opt/oracle/u1/oradata/OS80/system01.dbf SYSTEM /opt/oracle/u1/oradata/OS80/n311_t1.dbf USERDATA_N /opt/oracle/u1/oradata/OS80/csgrad_t1.dbf USERDATA_GRAD SQL> l 1 select tablespace_name, segment_name, segment_type, bytes, blocks, extents 2 from dba_segments 3* where owner = 'SCOTT' TABLESPACE_NAME SEGMENT_NA SEGMENT_TYPE BYTES BLOCKS EXTENTS SYSTEM BONUS TABLE SYSTEM SALGRADE TABLE SYSTEM WORKER TABLE SYSTEM TEMP_USERS TABLE SYSTEM LEDGER TABLE SYSTEM DEPT TABLE SYSTEM EMP TABLE SYSTEM PK_DEPT INDEX SYSTEM PK_EMP INDEX rows selected.