pga for ps4

1. directpath reads description In versions earlier than Oracle 11g, if a full table scan is performed on a large table, the wait event is: DB file scattered read; in 11g, if a full table scan is performed on a large table, wait event is: direct path read; that is, in 11 GB, full table scan of large tables directly reads data blocks into the PGA region of the session. (For more information, see the following example ). In 11g, data blocks are directl

Bkjia.com exclusive Translation]Oracle has made great efforts in simplifying memory management over the past few years. Since Oracle 9i implements automatic PGA management through the PGA_AGGREGATE_TARGET parameter, Oracle 10g implements automatic SGA management through the SGA_TARGET parameter, oracle 11g is surprisingly capable of fully automatic management of all the memory blocks of the database. It makes dynamic management of SGA and

| | | | --------------------------------------------------------------------------------------------------------------- --predicate information (identified by Operation ID):---------------------------------------------------4-acce SS ("T3".) ID "=" T4 "." t3_id ") filter("T3".) ID "=" T4 "." t3_id ") 5-filter (" T3 "). N "=1100) From the result of the return execution plan, we can see:1. T3 as the driving table and T4 as the driving table, both cost (a-time) and buffers are almo

Term definitionsActive Session Pool resource group or sub-plan number of currently active sessions allowedADDM Automatic Database Diagnostic Monitor (automatic DB diagnostic monitoringProgramASM Automatic Storage Management (Automatic storage Management)ASM Automatic Summary Management (Automatic profile Management)ASMM Automatic Shared Memory Management (automatic management of sharing RAM)ASSM Automatic Segment Space Management (automatic segment space management)ATO Automatic Tuning Optimizer

reverse is true: only one instance of a database operates on it. However, Oracle's real application cluster (real application Clusters,rac) is an exception, This is an option provided by Oracle that allows operations on multiple computers in a clustered environment so that multiple instances can mount and open a database (on a shared set of physical disks) at the same time. As a result, we can access this database from several different computers at the same time. Oracle RAC supports highly ava

):---------------------------------------------------4-access (" T3 "." ID "=" T4 "." t3_id ") filter (" T3 "." ID "=" T4 "." t3_id ") 5-filter (" T3 ")." N "=1100)From the results of the returned execution plan we can see:1. The cost (a-time) and buffers of the T3 are the same as the driver table and the T4 as the driver table.2. With T3 as the driver table, T3 Access once, T4 is also visited once; With T4 as the driver table, T4 Access once, T3 is also visited once3. Sorting required if the

secondary database under the/u01 file system, as well as the data pump files2. There must be a full database backup, or at least system-related tablespace backupThe following are the restrictions and constraints for applying table or partition recovery in Rman:1. sys user table or partition cannot be restored2. Tables and partitions stored in the Sysaux and system tablespace cannot be restored3. Restoring this table is not feasible when the remap option is used to restore a table containing a N

consists of an Oracle instance and an Oracle database. That is: Oracle Server = Oracle Instance + Oracle Database Oracle Instances Includes a memory structure (SGA) and a series of background processes (Background process), which together are called an Oracle instance That is: Oracle Instance = SGA + Background Process Oracle Memory Architecture Includes system global Area (SGA) and program Global (PGA) Oracle Memory structures = SGA +

SQL Server cannot create table as select directlyTo copy a table under SQL Server, think of Oracle under direct CREATE TABLE XXX as SELECT * from .... Can.But the result is wrong, Baidu found.SQL Server syntax is: SELECT * into Tablenew from TableoldInsert into select and CREATE table as performance test and create TABLE 2013-10-05 09:55:00Category: Linux1.Document DescriptionThe INSERT into Select and CREATE table as statements are often used in the work to copy the form data, and when the data

system global zone (SGA) and program global zone (PGA) Oracle memory structures = SGA + PGA SGA is shared by servers and background processes. PGA contains the data and control information of a single server process or a single background process. Unlike the SGA shared by several processes, PGA is In a region used by

Generally, we will use the memory of the Oracle instance to 80%-60% of the physical memory of the system (4G memory or above uses more than 80%, 2g memory uses 60%-70%)S = pga + sga_max_size = 80% memory)Db_cache_size = 60% sgaShared_pool_size = sga_max_size-db_cache_size-160m can also be set to around 35% sgaJava_pool_size = 64 mLarge_pool_size = 16 mLog_buffer = 2 m 1: 4 GB physical memory If it is 4000 mThenS = 3200 mFor OLTP (Sga = s * 80% = 2560

Scripts written in Bash can also be debugged, just like Python,perl and other interpreted languages. Create a new script named Servinfo and add executable permissions: Copy Code code as follows: $ VI Servinfo #!/bin/bash echo "Hostname: $ (Hostname)"echo "Date: $ (date)"echo "Kernel: $ (Uname-mrs)" $ chmod +x Servinfo With Bash-x to debug the above script, bash prints each line of script first, then prints out the results of each line of script: Copy Code c

. Configure IP addresses for different instances, associated access protocols, ports, and more. 3. The accessibility of an instance requires that the corresponding service for the instance be started. Notice here that the instance name and the instance's service name are not the same. The default instance's service name is MSSQLSERVER, and the named instance's service name is Mssql$instance_name. 4. The settings for the relevant functionality of the instance can be implemented through the peri

backup, or at least system-related tablespace backupsThe following are the restrictions and constraints for applying table or partition recovery in Rman:sys user table or partition cannot be restored• Tables and partitions stored in the Sysaux and system tablespace cannot be recovered• Restoring this table is not feasible when the remap option is used to restore a table that contains a NOT NULL constraint　10. Limit the size of the PGAPrior to Oracle 12c R1, there was no option to limit and cont

Tags: buffer file adjustment Automatic Management CAL business related user ICA--Memory allocationWhen you build a library, you can allocate system memory 50%-80% to Oracle and later adjust to your business.SGA, PGA distribution ratio:Oltp:sga%80, PGA%20Olap:sga%50, PGA%50Mixed: SGA%60, PGA%40 --SGA Automatic Managemen

Oracle memory structure and instance Management 1. Memory Structure: The overall structure of the Oracle database is as follows: Each Oracle database is composed of an Oracle Instance and a database (data file, control file, and redo log file). The so-called Instance is the medium for the user to interact with the database, you can operate a database by connecting to an instance. The instance is composed of a unified memory structure (SGA, PGA, UGA) a

tells us that oracle logs will generate a large number of logs. 3) actual log generation process The actual log generation process has some performance problems. The teacher drew a lot of pictures in the course. His diagram is casual, but it should be said that it has a meaningful meaning. The student himself did not draw his picture because he only wanted to use words to describe the course. The memory has a sharedpool, Buffercache and logbuffer correspond to the dbf and redolog on the disk. O

Best practices for knowing your limit and kicking % notfound I have started using bulk collect whenever I need to fetch large volumes of data. this has caused me some trouble with my dBA, however. he is complaining that although my programs might be running much faster, they are also consuming way too much memory. he refuses to approve them for a production rolout. what's a programmer to do? The most important thing to remember when you learn about and start to take advantage of features such as

closed, which is generated by DBA forcibly and the tablespace is offline)LCKn (0-9): blocks the process.Dnnn: scheduling process.Memory Structure (which we will focus on)Memory Structure = SGA (system global zone) + PGA (Program global zone)SGA is the memory area used to store database information, which is shared by database processes. It contains data and control information of the Oracle server. It is allocated in the actual memory of the computer

1,oracle architecture, process management, and structural components in detailUser process: A process that connects to a database server through which the user interacts with the database. However, the user process cannot interact directly with the database, and it must be connected to the server's component server process.Server process: An explanation of the SQL statements passed by the user process, responsible for commit and rollback, participating in IO. When the server Process is started,