Oracle

When doing some comparative kernel research on Oracle, the dump command is used to dump the information in the database into the trace file. This article simply describes using the dump command to dump the information in a data block into a trace

--oracle Common Performance Monitoring SQL statements--1SELECT * from SYS. V_$sqlarea WHERE disk_reads > 100;--2 waiting for the monitoring caseSELECT EVENT,SUM (DECODE (wait_time, 0, 0, 1)) "Prev",SUM (DECODE (wait_time, 0, 1, 0)) "Curr",COUNT (*) "

Where is the data dictionary of the In-memory join Group located in memory?A customer asked if the Join Group was used when using Oracle's In-memory function,So where are these join Group, located in memory?According to the results of colleagues '

Some time ago the customer called to say that since the database was moved after the database is always prompt session is not available, and customer communication to know that their connection to the database program is from the morning after the

Cause:The inconsistency of data events in the credit database resulted in the confusion of data (RAC cluster), inconsistent Plsql query time and database time, which seriously affected the business. Because I just met once, and with the MySQL time

MySQL table name and other case sensitive issues: http://blog.csdn.net/postnull/article/details/72455768;1 MySQL under Linux database name, table name, column name, alias casing rules are like this: 2 1 , database name and table name are strictly

Principle One: Note the connection order in the WHERE clause:Oracle uses a bottom-up sequential parsing where clause, according to which the connection between tables must be written before other where conditions, and those that can filter out the

how ORACLE produces a random number :D bms_random1, decimals (0 ~ 1)Select Dbms_random.value from dual;2. Decimal number within the specified range (0 ~ +)Select Dbms_random.value (0,100) from dual;3. Integers within the specified range (0 ~

: Network Disk DownloadOracle Plsql Instance Fine Solutions is a progressively decomposed, detailed PL/SQL Programming tutorial that uses real-world scenarios of experiments, examples, and exercises to introduce the required PL/SQL programming

In the case of query ordering in Oracle, if there are null values in the Sort field, the sort result may not be the result you want.such as SELECT * from Tabletest ORDER BY VISITS DESC overwrites the original SQL statement to: SELECT * from

Bo Master Small white One, recently is learning about linux,oracle knowledge. The content is written by the blogger in the online reference of a lot of content, hands-on success, due to Bo Master ability is limited, such as the discovery of errors,

Test installs three node Oracle 12C RAC, notebook configuration dual core I5 16g memory, each VM allocates 4G memory.During the installation of the database software, the primary instance restarts unexpectedly and the database software is

Believe that this error is not unfamiliar to everyone, only to install the use of Oracle is expected to have encountered this problem, the general is now used in PL/SQL connection to the Oracle database when the time occurs.The cause of this error

1. Static SQL vs. dynamic SQLThe Oracle compiled PL/SQL program block is divided into two types:The first is the pre-assembly (early binding), that is, the SQL statement during the program compilation has been determined, most of the compilation of

The data schema is also a model, which is the form of a database of operational means for providing information representation, and is a tool used in databases to surprise the real world. The data model is divided into 3 types according to different

Some simple command comparisons for Oracle and MySQL1) sql> Select To_char (sysdate, ' Yyyy-mm-dd ') from dual;Sql> Select To_char (sysdate, ' Hh24-mi-ss ') from dual;Mysql> Select Date_format (now (), '%y-%m-%d ');Mysql> Select Time_format (now (),

1 backup File ManagementIf you want to delete the previous backup, do not manually go to the directory to delete, you should use the Delete command in the Rman command mode, otherwise, although the physical backup file is deleted on disk, but use

CREATE [UNDO] tablespace tablespace_name[DataFile DATEFILE_SPEC1 [, DATEFILE_SPEC2] ...[{mininum EXTENT integer [k|m]| BLOCKSIZE integer [K]|logging clause | Force LOGGING| DEFAULT {data_segment_compression} storage_clause| [Online|offline]|

1. Summarize the syntax for querying 10-20 Records in Oracle, SQL Server, and MySQLOne: Oracle database notation:1:select * FROM (select RowNum RN, * from table name wher rownumwhere a.rn>102:select * FROM table name where rownumMinusSELECT * FROM

When truncate an Oracle table, an error occurs:ORA-00604: A recursive SQL Level 1 error occurredORA-00904: "CURRENT_SCN": Invalid identifierThe analysis is due to the fact that a materialized view is built on the table:Select log_owner,log_table