pga superstore

of data file collection. Segment: Is the space occupied by the object in the database: a large chunk of storage space reserved for data: Oracle's most basic storage unit, specifying 3, memory allocation (SGA and PGA) SGA when building databases: is the memory area used to store database information, This information is shared by the database process. It contains data and control information for the Oracle server, which is allocated in real memory on

corresponding server process to it. There is also a structure for the shared server, this structure is not a user process corresponding to a server process, will be coordinated through the scheduler processing, about the shared server connection, this article is not redundant.3. Server process and instance process interaction4. Instance and database process interactionThe above describes what the approximate interaction process is when we are doing database connection operations. Let's take a l

$sesstat S 6 WHERE N.NAME = ' session cursor cache count ' 7 and s.statistic# = n.statistic#), 8 (SELECT VALUE from v$parameter WHERE NAME = ' session_cached_cursors ') /c4> 9 UNION All Ten SELECT ' open_cursors ', Lpad (VALUE, 5), To_char (+ * used/value, ' 990 ') | | '% ' From (SELECT MAX (SUM (s.value)) used From v$statname N, V$sesstat S The WHERE N.NAME in (' opened Cursors current ', ' session cursor cache count ') s.statistic# = n.statistic# GROU

Tags: Oracle architecture user ManagementDatabase architectureDefined:The composition of the database, the working process, the composition and management mechanism of the data in the database.Compositioninstances, user processes, server processes, database files,Other files (parameter files, password files, archive files).Oracle's concept:Program Global Zone (PGA):Defined:A piece of memory that the server process uses to contain data and control info

Recently listened to Bosenry teacher's MySQL optimization Open class, this is my notes.Now let's talk about the two features of MySQL memory and I/O.First, MySQL Memory Features:1. There is also global memory and memory per session (each session is similar to Oracle's SGA and PGA), but for each session of memory, we do not assign it too large. If the memory allocated to each session is too large, it can cause the oom to occur. In high concurrency, inc

When it comes to query theory, you first need to know the architecture of Oracle. The database service consists of two parts: an instance and a database file. The examples section includes the SGA (System Global area) and the PGA (Progam Global Area) and the background process composition. Examples include: data files, control files, log files, parameter files, and so on.When the user writes the SQL statement to start the query, the first entry to the

-information of Rman backup is recorded show parameter spfile; -- pfile and SPFile convert each other Create pfile='/home/oracle/pfile.ora'from spfile ; -- Storage location dump; (*) Logical storage structure Tablespace: A table space can have multiple data files Segment segment: A table is a segment, a table segment, and an index segment Zone extent: the smallest unit of allocated space Block: Minimum storage unit 8k -- the size of the Block Show parameter db_block_size; (2) Process st

Memory Statistics~~~~~~~~~~~~~~~~~ Begin End------------ ------------Host Mem (MB): 16,338.5 16,338.5SGA Use (MB): 3,072.0 3,072.0PGA Use (MB): 805.1 861.7% Host Mem used for sga+pga:23.73 24.08Exception response:Physical read (blocks): 35,368.4 3,067.3Physical Write (Blocks): 6.8 0.6 Tota wait% DB Event Waits time Avg (ms) time wait Class ------------------------------------------------- -------------------- Direct Path read 912,622 306.336 79.2 Us

Tags: using IPCRM to clear the database HP UX memory utilization issuesTo account for the environment, is the real-time production database host network. HP-UX 11.31+oracle 10.2.0.4.0 RAC cluster.Two machines outdoor rac,essdb3 and ESSDB4 two machines.Physical memory 128g,sga allocated 64G,PGA 5G. Morning found ESSDB4 host glance run only 6G of free memory.Use the following command for a simple analysis:Sql> select distinct SID from V$mystat; Gets the

centralized data dictionary that users can use to build their own applications. Orcale represents data in the form of a two-dimensional table and provides SQL (Structured Query language) to perform basic database management functions such as querying, manipulating, defining, and controlling data. Orcale has a good portability, through its communication function, the microcomputer program can be the same as small or large computer orcale, and can pass data to each other. In addition, Orcale also

Label:Oracle performs SQL processing: syntax checking, semantic checking, parsing of SQL statements, execution of SQL, and return of results. The PGA is an area of memory that is independent of the SGA, and when the user process connects to the Oracle server, the Oracle server assigns the appropriate PGA to each server process, and when the server process finishes, Oracle automatically releases the memory s

Setting up Oralce automatic memory management Enabling Oracle Automatic memory management requires shutdown, restart 1. Determine the SGA PGA memory size: Copy Code code as follows: Show PARAMETER TARGET 2. Determine the maximum use size of PGA since database startup: Copy Code code as follows: Select value from V$pgastat where name= ' maximum

Tags: style blog ar color OS using SP strong onFirst, memory adjustmentOracle 11g, Oracle unified the SGA with the PGA, the sum of the Memory_target parameter settings, that is, Max (SGA+PGA) Alter system set sga_max_size=1500m Scope=spfile;If the error is set to Sga_max_size>=memory_target (not equal, the PGA requires at least approximately more than 10 m of mem

Ext.://http://blog.chinaunix.net/uid-23177306-id-2531235.htmlFirst, direct path read1. Wait events associated with direct read. When Oracle reads data blocks directly into the PGA (Process Global Zone) of the session, it bypasses the SGA (System global Zone). Data in the PGA is not shared with other sessions. That is, this part of the data read is used on its own, not in the shared SGA.2, when the sort oper

Linux.Action: Refer to documentation for a list of supported operating systems. Or, size/dev/shm to be at least the SGA_MAX_SIZE on each Oracle instance running on the system. You can also use the search function of the official document to search for error codes and find corresponding explanations and solutions. Setting Memory Target at Instance Startup on LinuxStarting with Oracle Database 11g Release 1 (11.1), Oracle provides the option of automatically managing SGA and

performance information and send it to the prediction model, such as linear regression, which accurately tells you to change the Global region of your System, System Global Area, SGA) the number of times the internal structure is correct.ListingExamples of using such performance information are provided. This script will generate a continuous total of database buffer failure rates over a period of time and referenceStats $ librarycacheTable.The output of this script indicates that you need to p

and you can see the explanation of the error code.ORA-00845: MEMORY_TARGET not supported on this system Cause: The MEMORY_TARGET parameter was not supported on this operating system or/dev/shm was not sized correctly on Linux. Action: Refer to documentation for a list of supported operating systems. Or, size/dev/shm to be at least the SGA_MAX_SIZE on each Oracle instance running on the system. You can also use the search function of the official document to search for error codes and find corr

The content of this lecture includes: 1. Description of memory components in SGA 2. Use automatic shared memory management 3. manually configure the SGA Parameters 4. Configure Automatic PGA Memory Management I. SGA memory components Database buffer cache: Data cache Redo log buffer: stores the redo log cache. Shared pool: stores data dictionary and library cache Large pool: Optional. It is used to support parallel DML, asynchronous I/0, uga zone of t

is created. 3. Memory Allocation (SGA and PGA) 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 where the Oracle server resides. If the actual memory is insufficient, it is written into the virtual memory. PGA: contains the data and control inf

Setting oracle automatic memory management to enable oracle automatic memory management requires shutdown, restart 1. determine the sga pga memory size: show parameter target 2. determine the maximum pga usage since the database is started: select value from v $ pgastat where name = 'maximum PGA allocated'; 3. calculate the memory_target size: memory_target = sga