one. Adaptive cursor Sharing (adaptive Cursor sharing) Description
1.1 ACS Overview
Binding variables Enable Oracle DB to share a single cursor for multiple SQL statements to reduce the amount of shared memory used for parsing SQL statements.
More than 10 o'clock in the evening, the leader suddenly gave a big job, let's deploy an environmental requirement as follows:os:centos6.5jdk1.8tomcat8.0.22oracle-11gInstantly feel the MoeWhat is a JDK? I've never done it before, and there's only
[Email protected] ~]#/u01/app/orainventory/orainstroot. SH /u01/app/orainventory.adding Read,write for group. Removing read,writefor/u01/app/orainventory to Oinstall. The execution of the script is complete.[Email protected] ~]#/u01/app/11.2.0/grid/
Oracle's architecture is broadly divided into two parts: Instance (instance) and database.
Instance (example) : The SGA is mainly included in Oracle Instance and some processes (for example: Pmon, Smon, Dbwn, LGWR, CKPT, etc.). If a user's
*sql optimization based on ORACLE11GR2 reading notes * Third, cursor in OracleThe cursor in Oracle is a vector of SQL parsing and execution in an Oracle database and is a data structure for C (Oracle is written in C).There are two types of cursor in
RHEL6 ASM installation of Oracle 11g R2 tutorial directory:
I. Preparations before installationIi. Install the grid infrastructure3. Install database software4. Create a listener5. Create a database instance
I. Preparations before installation
1.1
Oracle-07445 [kgghash]: Oracle BUG causes the process to be killed when updating the LOB FieldSymptom:The user reports that a DB connection is accidentally killed. The following information is found in the alert Log during troubleshooting:Mon Apr 22
With the specific input values, the selectable rate (selectivity) of the Where condition of SQL and the number of rows (cardinality) of the result set may vary, The value of selectivity and cardinality directly affects the CBO's estimate of the cost
Oracle-07445 [kgghash]: Oracle BUG causes the process to be killed when updating the LOB FieldSymptom:The user reports that a DB connection is accidentally killed. The following information is found in the alert Log during troubleshooting:Mon Apr 22
SELECT * FROM table where id =?Similar to the above SQL, if you do not have to bind the variable, each time Oracle will be considered a different SQL, will be generated at each execution of the execution plan, and the execution plan generation is
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.