FBDA -- 3 : Support for TRUNCATEs
One of the points in the previous post was how ADD and DROP Column commands are supported in FBDA.Let's look at support for TRUNCATEs.(Just to prove that I am not using the Undo tablespace for the AS...
View ArticleFBDA -- 4 : Partitions and Indexes
Continuing our investigation of the FBDA architecture.oracle@ora12102 Desktop]$ sqlplus hemant/hemantSQL*Plus: Release 12.1.0.2.0 Production on Tue Apr 5 23:25:10 2016Copyright (c) 1982, 2014, Oracle....
View ArticleFBDA -- 5 : Testing AutoPurging
Tracking data changes after one row added (ID_COLUMN=2000) on 06-AprSQL> select systimestamp from...
View ArticleRecent Blog Series on Compression
These have been my recent posts on Compression.1. 1. BASIC Table Compression (Feb-16)2. 1b. More on BASIC Table Compression (Feb-16)3. 2. Compressed Table Partitions (Mar-16)4. 3. Index (Key)...
View ArticleFBDA -- 6 : Some Bug Notes
Some MoS documents on FBDA Bugs1. Bug 16454223 : Wrong Results (more rows than expected)2. Bug 16898135 : FBDA does not split partitions (resulting in rows not being purged)3. Bug 18294320 :...
View ArticleOnline Relocation of Database File : ASM to FileSystem and FileSystem to ASM
There have been few published examples of the online datafile relocation feature in 12c. The examples I've seen are on filesystem.Here I show online relocation to/from ASM and FileSystem.SQL>...
View ArticlePartition Storage -- 1 : Default Partition Sizes in 12c
11g 11.2.0.2 introduced a change whereby the default Initial Extent of a Table Partition was 8MB. However, this did not apply to Index Partitions which could still start with 64KB extents in an...
View ArticlePartition Storage -- 2 : New Rows Inserted in 12.1 Partitioned Table
Following up from the previous post, given the current sizes of the Partitions (The underlying Tablespace is AUTOALLOCATE) :SQL> col segment_name format a30SQL> col partition_name format...
View ArticlePartition Storage -- 3 : Adding new Range Partitions with SPLIT
Building on the Partitioned Table in the previous two blog posts...We know that the Table is a Range Partitioned Table. With a MAXVALUE Partition, the only way to add new Partitions is to use the...
View ArticlePartition Storage -- 4 : Resizing Partitions
Building on Posts 2 (Adding Rows) and 3 (Adding Partitions) where we saw Table Partitions using 8MB Extents ..... is there a way to "resize" Partitions to smaller Extents (and, maybe, lesser space...
View ArticlePartition Storage -- 5 : Partitioned Table versus Non-Partitioned Table ? (in...
Reviewing my second blog post in this series, I found it strange that Partition P_100 (populated by Serial Inserts of 1 row, 100,000 rows, 500,000 rows and 500,000 rows) had such a High Water Mark.For...
View ArticlePartition Storage -- 6 : Revisiting Partition HWM
After the curious finding in my previous blog post, where a Partition's HighWaterMark was noticeably higher than that for a non-Partitioned Table but then shrunk on a MOVE operation, retrying the same...
View ArticlePartition Storage -- 7 : Revisiting HWM - 2 (again)
Revisiting the previous test case, but with a larger AVG_ROW_LENSQL> create table part_table_large(id_column number(6), data_col_1 varchar2(100), data_col_2 varchar2(100)) partition by range...
View ArticleFBDA -- 7 : Maintaining Partitioned Source Table
Taking up the TEST_FBDA_PARTITIONED table, let's look at a couple of Partition Maintenance operations.SQL> select partition_name, high_value, num_rows 2 from user_tab_partitions 3 where table_name...
View ArticleCompression -- 6 : Advanced Index Compression
Earlier, I had covered Index (Key) Compression which is included in the Enterprise Edition.In Key Compression, the DBA must specify the Prefix (i.e. number of leading columns in a composite index) that...
View ArticleCompression -- 6b : Advanced Index Compression (revisited)
Following up on my earlier post on 12.1.0.2 Advanced Index Compression, one of my readers asked what would be the difference if I reversed the order of columns in the chosen index.My defined index was...
View ArticleCompression -- 7 : Updating after BASIC Compression
In the first blog post on compression, I had shown BASIC Compression and also the effect of executing an UPDATE on a table with BASIC compression.To expand on the them of UPDATEs of BASIC compression...
View ArticlePartition Storage -- 8 : Manually Sizing Partitions
As demonstrated in the first post in this series, the default size for Table Partitions is to start with an I nitial8MB Extent. The fourth post demonstrated how to resize a Partition that has already...
View ArticleTRUNCATEing a Table makes an UNUSABLE Index VALID again
Here's something I learned from Jonathan Lewis sometime ago.If you set an Index to be UNUSABLE but later issue a TRUNCATE TABLE, the Index becomes VALID again --- i.e. the Index gets updated with rows...
View ArticleRecent Blog Series on Partition Storage
These have been my recent posts on Partition Storage.1. 1. Default Partition Sizes in 12c (Apr-16)2. 2. New Rows Inserted in 12.1 Partitioned Table (Apr-16)3. 3. Adding new Range Partitions with...
View Article
