• [20200129] sub cursor does not share bind_ EQUIV_ FAILURE.txt


    [20200129] sub cursor does not share bind_ EQUIV_ FAILURE.txt –//The production system encountered a large number of bind again_ EQUIV_ Failure causes a sub cursor. I looked at the situation I encountered in my previous tests.–//Links =>[20180613] sub cursor does not share bind_ EQUIV_ FAILURE。–//Other people have suggested to me that the problem may […]

  • [20200211] using DBMS_ SHARED_ POOL.MARKHOT And SQL_ Calculation of id.txt


    [20200211] using DBMS_ SHARED_ POOL.MARKHOT And SQL_ Calculation of id.txt –//Previously written, using DBMS_ SHARED_ POOL.MARKHOT Tag hot SQL_ ID, so the same SQL statement uses different SQL_ id.–//Link: =>[20171110] same SQL statement_ Can Id be different–//I’m curious to know how Oracle calculates SQL in this case_ It’s not. –//Correction: SQL statement uses DBMS_ […]

  • Oracle export warning & quot; exp-00003: storage definition of segment (0,0) not found & quot; resolved


    Environmental Science:Centos7.4 oracle11.2.0.4 (building RAC cluster) Problem Description:When using exp command to export, some tables prompt “exp-00003: storage definition of segment (0,0) not found” warning. Cause of the problem:This problem is caused by the exported data table is empty. Oracle 11gr2 does not allocate segments to save space when there is no data in the […]

  • Row column conversion after Oracle 11


    After Oracle 11, there is a new method of row column conversion. The following is the dredged code, please rest assured to use… With AA as ( Select A,B,C,row_number() over (partition by B order by b) D from (   Select 10 A, 11 B, 12 C from dual   union    select 20,11,22 from […]

  • Implementation of Oracle row result total


    The implementation of Oracle row result total is mainly applied to the collection of date results. The following is the specific implementation code. With AA as (   select ‘A’ tNo ,  10 B from dual   union   select ‘B’ ,  20 from dual   union  select ‘A’ ,  30 from dual ) select […]

  • [20200223] optimization of latch and mutext.txt


    [20200223] optimization of latch and mutext.txt –//I have been testing DBMS for some time_ SHARED_ POOL.MARKHOT Identify hot objects and optimize SQL statements.–//Some people asked me that I spent a lot of energy on meaningless work. In fact, I used to optimize SQL statements more on Io and reduce logical reading of SQL statements.–//Little attention […]

  • Oracle interval ‘1’ year reported an error today


    2.28, the customer WeChat official account updated the bill list function: the account records found in the owners’ feedback group were not their own, and the users’ numbers were written and killed after verification and speculation. ok Working from home is a little sloppy. Let’s understand. On February 29, Saturday, I didn’t wake up from […]

  • [12C] database flashback and data guard


    In the data guard environment, the standby database can be opened in read-write mode by using the flashback feature of the database, which is used to perform some kind of test work on the primary database. After the test, the database can be flashed back to the previous state as a backup to continue to […]

  • [12C] learn more about Oracle flex ASM and its advantages


    brief introduction Oracle Real Application Cluster (RAC) is a famous product in Oracle solutions, which is used to maintain the high availability of business data. Oracle RAC allows all cluster nodes to share load, and adopts n-1 fault-tolerant configuration to deal with node failure, where n is the total number of nodes. Oracle RAC has […]

  • [12C] switch between snapshot database and physical backup database (cloud control mode)


    This article demonstrates how to experiment with cloud control to switch between snapshot database and physical backup database. 1 switch from physical backup database to snapshot database 1) Switch to physical backup library orcldg 2) Click Convert in the standby database column 3) Click to continue 4) To confirm the conversion of the database, click […]

  • [12C] new feature: using RMAN to recover tables or table partitions


    When a table is misoperated, such as deleting data, drop table, or truncate table, we can restore it by using flashback table, flashback drop, or tspitr. However, in the following scenarios, the above recovery technology will be helpless: The table logic is damaged or the purge option is used to delete; When Undo is not […]

  • [12C] Oracle Enterprise Manager cloud control 12C architecture


    Oracle Enterprise Manager cloud control 12C (referred to as cloud control, CC or 12C) is a solution for Oracle to manage a complete it environment, including Oracle products and non Oracle products. Cloud control collects the information of enterprise computing system, and integrates the management of this information into a central database. Cloud control displays […]