securefile

The Securefile feature is a fully redesigned implementation of the large object (LOB) storage format in Oracle 11g, the original LOB storage format now known as Basixfile, which is still the default storage method, but the Securfile keyword opens a new storage method, It allows encryption, use of compression to save space and data de-duplication. 　　Initialization parameters The Securefile feature is availa

OracleSecureFile Oracle SecureFile Function The SecureFile function is a completely re-designed implementation of the large object (LOB) storage format in oracle 11g. The original LOB storage format is now called BASIXFILE, and it is still the default storage method, however, the SECURFILE keyword enables a new storage method, which allows encryption, space saving by compression, and data duplication elimi

The key reason for upgrading a large object (Large object, LOB) storage capability is the increasing demand for data security in Oracle 11g, which focuses on expanding transparent data encryption for LOB and tablespace (transparent data encryption, TDE) features to improve data security and explain how these features protect complex, unstructured data, such as medical Digital Image communication (Digital Imaging for communication of medical information, dicom Object Oracle 11g New

: Try to create all lobs as Securefile lobs, but only automatic segment space management can be(ASSM) any lob outside the tablespace is created as a basicfile lob? Force: Forces all lobs to be created as Securefile lobs? Permitted: Allow Securefiles to be created (default value)? Never: Prohibit creation of securefiles? IGNORE: Disable creation of securefiles and ignore force creation of basicfiles with SEC

I have never paid attention to the data storage methods in Oracle, because most of them use metadata stored in Oracle relational databases. Today, I happened to see a description about Oracle 11g data definition, which is collected as follows: 1. Oracle Data Division Oracle considers that data can be divided into three types: 1) Structured Data: This type of data refers to data that can be stored and managed using relational database tables; 2) unstructured data: This type of data refers to var

Oracle SecureFiles was introduced in Oracle 11g. It has some advantages that traditional large objects (which have been renamed BasicFile LOB) do not have. Oracle SecureFile LOB supports Smart Data Compression. It is a deduplication method that eliminates multiple storage of identical data copies. It also supports other features that use large objects to improve performance. One of the most useful new features is the transparent data encryption featur

segment-space management, Oracle Database uses the FREELISTS storage parameter to improve performance of space management in OLTP systems by increasing the number of insert points in the segment.(2) In tablespaces with automatic segment-space management, this parameter is ignored, because the database adapts to varying workload.In tablespaces with manual segment-space management, for objects other than tablespaces and rollback segments, specify the number of free lists for each of the free list

, so no matter how the test, can not be back to the customer scene. The table I created is as follows: CREATE TABLE Wrong_tab_securefile_cache (ID number,Clob_data CLOB)LOB (Clob_data) STORE as Securefile cacheTablespace users; The correct table is established in the following ways:CREATE TABLE Tab_securefile_cache (ID number,Clob_data CLOB)LOB (Clob_data) STORE as Securefile (cache)Tablespace users; Ju

CLUSTER lobindex INDEX INDEX PARTITION lobsegment TABLE subpartition INDEX subpartition LOB PARTITION LOB subpartition ROLLBACK TYPE2 UNDO DEFERRED ROLLBACK temporary CACHE SPACE HEADER UNDEFINED SEGMENT_SUBTYPE VARCHAR2(10) Subtype of LOB segment:

, Nchar,nvarhcar2, Long, DATE, raw, long raw, BLOB, CLOB, TIMESTAMP (9i+), BINARY FLOAT, BINARY DOUBLE (10g+) Full support for LOB fields: Supports CLOB, NCLOB, and BLOBs CLOB supports big endian and little endian byte order Support for LOB partitions, sub-partitions Support for cases where different LOB columns use different chunk size in the same table CLOB data can be exported to the same file as other columns, or stored in a separate file LOB columns can still be exported witho

#ADLOB45281RETENTION Parameter for BasicFiles LOBsTo Determine whether LOB segment is using RETENTION or PCTVERSION, use the following statement:SQL> select COLUMN_NAME, SECUREFILE, PCTVERSION, RETENTION from dba_lobs where OWNER = upper (' owner') and TABLE_NAME = upper (' TABLE_NAME ');COLUMN_NAME SEC PCTVERSION RETENTION-----------------------------------------------------FILE_DATA NO 900Note: If You 've a value for both PCTVERSION and RETENTION c

tools support tables that use basic table compression, OLTP table compression, and hybrid column compression (hybrid column compression is one of the features of Oracle exadata) The logical standby and logminer tools support tables that contain the securefile lob field. Compression and encryption on the securefile lob field are also supported. (De-duplication and fragment-based operations are not supporte

LOB segment are using RETENTION or pctversion, use the following statement:Sql> Select Column_name,securefile,pctversion,retention from Dba_lobs where Owner=upper (' owner ') and TABLE_ Name=upper (' table_name ');column_name SEC pctversion RETENTION------------------------------ --- ---------- ----------File_data NO 900Note:if you ' ve a value for both pctversion and RETENTION columns, this is incorrect output and to really know which opt Ion the LO

to this instance is being monopolized by the present instance. 2, Scur, a current mode blocks, shared with the other instances is being instance share 3, CR, a consistent read (stale) block image consistent read 4, read, buffer is reserved for a blocks being read from disk reading chunks from disks 5, MREC, block A, media recovery mode is in the medium recovery model 6, Irec, a block in instance (crash) recovery mode is in the instance recovery mode 0, ' free ', 1, ' Xcur ', 2, ' scur ', 3, ' C

where id = 1; SQL> selectid, name, dbms_rowid.rowid_relative_fno (rowid) file #, dbms_rowid.rowid_block_number (rowid) block # from gyj1_t80 where id = 1; Id name file # BLOCK # -------------------------------------------------- 1 gyj1 5 581 Select LRU_FLAG, lower (BA), TCHfrom x $ bh where file # = 5 and dbablk = 581; SQL> select LRU_FLAG, lower (BA), TCH, decode (state, 0, 'free', 1, 'xcur', 2, 'scur' 2, 3, 'cr ', 4, 'read', 5, 'mrec', 6, 'c C', 7, 'write', 8, 'Pi ', 9, 'memory ', 1

support these functions. (in Oracle, you can apply dbms_session in the package to set context to implement user variables ). 47. Oracle does not distinguish the TIME and DATE types. Oracle's Date type is actually a DATETIME type (but it supports a larger DATE range than MySQL ). 48. compared with MySQL, Oracle has much better stored procedures and trigger functions and performance. do not use them habitually. 49. if you need to write a stored procedure in Oracle, remember to spend some time bef

. if you need to write a stored procedure in Oracle, remember to spend some time before coding to see if Oracle has a corresponding built-in package. you will find that most of the problems have been solved, or at least a large amount of basic code is already there. 50 if you use BLOB or TEXT in MySQL, you may migrate them to BLOB and CLOB in Oracle. however, unlike MySQL, Oracle does not transparently materialized the data. in most cases, this is indeed a good thing, but it also means that if y

(CompressionUnit) to store data, stores the information of each column in a group of (many rows) rows, and then compresses the data. This can save more space. (Originally, it was just a block reference, but now it is a multi-block reference, which definitely saves more space) But likewise, because of this storage structure, when one row of data is updated, locks all rows in a Logical Compression Unit. I am not selling OracleDatabase, so I will introduce the content about HSCC here. Finally, let

function to redo logs to the physical standby database in real time, even if it is read-only ), this function is similar to the function of querying read-only standby databases when redo logs are being applied in real time. It provides an optional solution for the read-only data warehouse to use basic replication. But there is an important exception: There is no way to deal with any significant delay in redo logs on the physical standby database. Oracle 11gR2 provides a new session-level parame

), as well as a series of command-line tools that can be used to monitor file system events. Inotify-tools is written in C, except that it requires the kernel to support inotify, and does not depend on others. Inotify-tools provides two tools, one is inotifywait, it is used to monitor file or directory changes, and the second is Inotifywatch, it is used to count the number of file system accessinstallation process root. ~:wget http://github.com/downloads/rvoicilas/inotify-tools/inotify-tools-3.1