Oracle

I got a colleague asking for help today, saying that there is a select query that runs for more than a minute on Oracle, and he hopes to produce results within 5s, as follows: Select/*+ Parallel (SRC, 8) */distinct src.systemname as SystemName,

Oracle's security is divided into four parts, namely user management, access control, data protection and monitoring, specific reference to the [Oracle] Database Security Overview http://blog.csdn.net/u010415792/article/details/9008089 One of the

If Oracle unfortunately encounters undo corruption in operation, the best approach is full recovery, but if there is no backup, you can take an unconventional approach (taking advantage of the hidden parameters of Oracle) and if undo contains

AWR's data consists of two main components: 1 The system load and performance statistics stored in memory, mainly through the v$ view query; 2 The Mmon process periodically saves in-memory awr data to the Sysaux tablespace in a snapshot (snapshot)

We all know that every SQL statement in Oracle needs to be parsed before it is executed, which is divided into soft parsing and hard parsing. There are two types of SQL statements in Oracle, one for DDL statements (data definition language), they

Oracle MySQL Enterprise Section Thread_pool_algorithm: Connection concurrency scheduling algorithm, the default value of 0 using a conservative low-level concurrency algorithm, tested performance results are good. A value of 1, the concurrent

The two days to restore Oracle really headaches, my environment is cenos5.3+oracle11g, the official server's database instance path is:/app/oracle/oradata/databar, originally only backed up the files in this

Although indexes are not always faster than full table scans, many times we want Oracle to use indexes to execute certain SQL, at which point we can force SQL to use index through the index hints. The format of the Index hints is as follows: /*+

Experiment Description: (1) Create 2 table spaces first. Create Tablespace User01 DataFile '/opt/oracle/oradata/ocp/user01.dbf ' size 1M; Create Tablespace User02 DataFile '/opt/oracle/oradata/ocp/user02.dbf ' size 1M; (2) Create a table on

Several project groups have already started using Oracle's Full-text indexing. Oracle's lexical analyzer is not smart enough for the lexical analysis of the ZHS16GBK character set, and can only be mechanically matched to the word unit. There is a

Our IDC core data area to the DMZ in the Thursday has experienced a very strange failure. Although I have judged the issue of non-Oracle from the outset, since the application of multiple Oracle databases connecting to the core data area has the

It's hard to know what the reason is when a system slows down in performance. Is it a memory leak, a disk subsystem bottleneck, or a specific application that has limited scalability? There are ways to discover and understand the root cause of

Database environment Leo1@leo1> select * from V$version; BANNER -------------------------------------------------------------------------------- Oracle Database 11g Enterprise Edition release 11.2.0.1.0-64bit Production Pl/sql Release 11.2.0.1.0

Over the past decade, Oracle has become one of the most professional databases in the world. For IT professionals, it is important to ensure that Oracle's powerful features are used to improve the productivity of their companies. One of the most

We know that user-owned role permissions are not available in stored procedures. Such as: 　　SQL> select * from dba_role_privs where grantee='SUK';　　GRANTEE GRANTED_ROLE ADMIN_OPTION DEFAULT_ROLE------------ ------------SUK DBA NO YESSUK CONNECT NO

Absrtact: The development of dynamic SQL program is summarized, and some development techniques are given according to the author's actual development experience. Key words: Dynamic Sql,pl/sql, high performance 1. static sqlsql and dynamic SQL

Oracle storage of large text has been a thorny issue. First, the storage database: "Defining variablesJava.sql.Connection Conn; Database Connection objectsString SQL;Long ID;ResultSet rs;Statement Stmt,stmt1;java.sql.drivermanager.registerdriver

Oracle allows up to 148 enabled when user roles are enabled. In fact, this limit is strange, because 148 and 2 of the power difference is large, do not know what the reason for Oracle to determine this value: Sql> CREATE USER U_role identified by

If you use DBCA to establish a RAC database, the Remote_listener parameters are configured on each node by default, so the previous Test load_balance was tested in the presence of Remote_listener. Here is a test to remove the effect of

There are two ways to optimize Oracle's optimizer: Rule-based optimization method: rule-based optimization (RBO) Optimization method based on cost or statistic information (cost-based OPTIMIZATION:CBO) Rbo: When the optimizer analyzes SQL