Oracle Tidbits – November 2015

Oracle *daily* TidBits” (#oratidbit) published at https://www.facebook.com/oraclenotes on weekdays in November 2015. You will also see these tidbits, one tidbit at a time, for each page refresh on the right side of this blog as well… Hope you find these helpful to learn something new or to remind you of its existence and use…

Publish Date TidBit
2-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): Flashback single PDB possible.
3-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): The number of PDBs you create in Container Database Architecture increases to around 4096.
4-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): Online PDB clone. Currently to clone a PDB, it must be in read only mode.
5-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): Apply PSU and smaller patches on standby first, before applying to primary.
6-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): AWR will work on Active Data Guard Database, so you can tune your reporting database.
9-Nov #oratidbit DB 12cR2 Feature (heard from #oow15): A diskgroup in ASM can have file groups to group files belonging to PDBs or databases.
10-Nov #oratidbit SQL Plan Management (SPM) is a preventative mechanism that enables the optimizer to automatically manage execution plans, ensuring that the database uses only known or verified plans.
11-Nov #oratidbit SQL Plan Management (SPM) Evolve Advisor (new in 12c) is a SQL advisor that evolves plans that have recently been added to the SQL plan baseline. The advisor simplifies plan evolution by eliminating the requirement to do it manually.
12-Nov #oratidbit SQL Management Base (SMB) is a logical repository that stores statement logs, plan histories, SQL plan baselines, and SQL profiles. The SMB is part of the data dictionary and resides in the SYSAUX tablespace.
13-Nov #oratidbit DBA_SQL_MANAGEMENT_CONFIG view shows the current configuration settings for the SQL Management Base (SMB). The SMB stores information that the optimizer can use to maintain or improve SQL performance. Use DBMS_SPM.CONFIGURE to change SMB setting.
16-Nov #oratidbit SQL Profiles and SQL plan baselines are internally implemented using hints. SQL plan baselines are proactive, whereas SQL profiles are reactive.
17-Nov #oratidbit Use DBMS_SPM.CREATE_STGTAB_BASELINE procedure to create a staging table that enables to transport SQL plan baselines from one database to another.
19-Nov #oratidbit Zone maps in #DB12c reduce the I/O and CPU costs of table scans by tracking the sets of contiguous data blocks, or zones, in which certain column values are stored.
20-Nov #oratidbit In #DB12c ROW LEVEL LOCKING clause of CREATE TABLE can be used to control whether row level locking is used during DML operations for tables compressed with Hybrid Columnar Compression.This improves the performance of DML operations when accessing Hybrid Columnar Compressed data.
23-Nov #oratidbit In #DB12c using the INVISIBLE attribute in CREATE VIEW, you can make a column in a view invisible. By default, view columns are VISIBLE regardless of their visibility in the base tables, unless you specify INVISIBLE.
24-Nov #oratidbit on Oracle Database Appliance, ORAChk tool can be accessed as “oakcli orachk” from either ODA node.
25-Nov #oratidbit Trace File Analyzer (TFA) diagnostics collection is performed on ODA as “oakcli manage diagcollect”
26-Nov Thank you to all #oratidbit followers! Happy Thanksgiving!!
27-Nov #oratidbit on Exadata, use the dcli command to execute cellcli and other commands on remote cells. dcli (distributed command line interface) uses ssh.