SQL & PL/SQL :: Using Function-based Indexes In SE?
Mar 29, 2012
I have noticed a very questionable phrase on an article updated in 2011: "Oracle SE may allow you to create a function-based index, but you must pay for an EE license to use FBI's." [URL] Is this true? I have tested a FBI on my SE and works just fine.
Connected to:
Oracle Database 11g Release 11.2.0.3.0 - 64bit Production
SQL> create table t ( col varchar2(10));
Table created.
SQL> create index t_idx on t(upper(col));
Index created.
SQL> insert into t values('a');
[code]....
View 11 Replies
ADVERTISEMENT
Jun 15, 2012
Is anyway to create function based index for group function columns.
For example
select max(timestamp),min(age),averge(sal).... ... .. from tab;
View 5 Replies
View Related
May 28, 2013
Oracle Version: 11gR2: 11.2.0.1.0 - 64bit
OS: Linux Fedora Core 17 X86_64
Currently, I'm reading the online book Oracle Concepts, Chapter 3: 3 Indexes and Index-Organized Tables, section: Reverse Key Indexes in order to understand this topic.
As I understand for each pair of (key, rowid) in the index structure, the rowid for each row in the table obviously remains the same but the bytes of the key are reversed before the key is stored. So for example on a 32 bit machine (just an example) a key = 10 AB CD EF will be stored as FE DC BA 01 , am I right?
According to the documentation, this becomes interesting in RAC environments in order to remove a hot spot from the index (when multiple instances repeatedly modify the same block) with the disadvantage that in some cases there cannot be Index Range Scan any more as data in the index is not sorted by column key when it is stored.
I was just curious to see how bytes of each key are reversed and after a bit googling I found an article where Tom Kyte shows with an example by using dump function (which as I understand gives the internal representation of a given expression) the difference in the sequence of bytes. Here is the link
[URL]
So based on his instructions I tried to do my own test, yet I don't get the same result, that is, the bytes are not reversed for me once we rebuild the index by REVERSE key word.
I'm going to write down here the test that I did, where is/are my error(s)
Test Case:
(I use a copy of the employees table in hr sample schema)
SQL> CREATE TABLE emp_test AS SELECT * FROM hr.employees;
Table created.
SQL> CREATE INDEX emp_test_idx ON emp_test(first_name);
[code]...
Now, a test SQL Query using the index we've just defined (just for giving an example)
SQL> SELECT first_name,
2 dump(first_name, 16) as dump_result
3 FROM emp_test
4 WHERE first_name = 'Kelly';
FIRST_NAME DUMP_RESULT
-------------- ----------------------------------
Kelly Typ=1 Len=5: 4b,65,6c,6c,79
[code]...
So, according to the above Execution plan, Oracle does an Index Range Scan using the index that I defined on my table that is, emp_test_idx. According to the output of dump, the key (first_name) in that index is stored (in terms of bytes) as 4b,65,6c,6c,79
SQL> SELECT chr(to_number('4b', 'xx')) ||
2 chr(to_number('65', 'xx')) ||
3 chr(to_number('6c', 'xx')) ||
4 chr(to_number('6c', 'xx')) ||
5 chr(to_number('79', 'xx')) first_name
6 FROM DUAL;
FIRST_NAME
--------------------
Kelly
Which as we can see corresponds to the first name 'Kelly', the first name we specified in the above SQL query.
Now let's rebuild the index
SQL> ALTER INDEX emp_test_idx REBUILD REVERSE;
Index altered.
SQL>
Once the index keys have been reversed, I run the very same query in order to see the difference
SQL> SELECT first_name,
2 dump(first_name, 16) as dump_result
3 FROM emp_test
4 WHERE first_name = 'Kelly';
[code]...
So the second time after the index has been reversed, I still get the very same sequence of bytes, that is, 4b,65,6c,6c,79, whereas I expected to get 79,6c,6c,65,4b (that is, the reversed order of the initial bytes sequence)
View 8 Replies
View Related
Mar 3, 2011
I have partition based table one the basis of year month. And we have 8 local indexes on this table. Every month we have to create a new partition and load data into this partition and the volume of the data is around 14million and the load process is taking long time due to indexes. Is it possible to drop the indexes from particular partition?
View 8 Replies
View Related
Jun 27, 2011
I have a table which sees a lot of use for queries
CREATE TABLE CASE_STAGE
(
ID NUMBER(9) NOT NULL,
STAGE_ID NUMBER(9) NOT NULL,
CASE_PHASE_ID NUMBER(9) NOT NULL,
"CURRENT" NUMBER(1) NOT NULL,
--and other columns
)
ID is a primary key
CASE_PHASE_ID is a foreign key
"CURRENT" should only ever have values of 0 or 1. When it has a value of 1 it is unique for that CASE_PHASE_ID
What I have tried that doesn't work is
create unique index case_stage_F_IDX1 on case_stage("CURRENT", case_Phase_id) which gives me
ORA-01452: cannot CREATE UNIQUE INDEX; duplicate keys found
What is the correct syntax, something like ("CURRENT"=1,case_phase_id) seems right but fails with an error about a missing bracket. Do I need to use a CASE statement here?
View 1 Replies
View Related
Jun 22, 2011
I have created a function based index(FBI) with trim(header_date), but when i query the table by passing the hardcoded date, it is not working and i have to manually apply trim to get the result?
my query after applying FBI is
select * from abc where header_date = '21-JUN-11', no results are returned and when i apply trim to header_date it works fine .
View 4 Replies
View Related
Feb 22, 2012
I have a table which has 4M records
This table has a query where one of the condition is
AND STATUS <> 'C'
Now the data is as following
select count(*) record_count, status from new_business group by status;
record_countstatus
4298025C
15N
13Q
122S
I want to know if following index would be useful in this case while the condition in where clause is
"AND STATUS <> 'C'"
create index nb_index_1 on new_business(case when status in('N','Q','S') then 1 else NULL end);
Or
create index nb_index_1 on new_business(case when status ='N' then 'N' when status='Q' then 'Q' when status='S' then 'S' else NULL end);
I tried it on a sample table but the index is simply not picked up even when hinted following are the db level settings
query_rewrite_enabled string TRUE
query_rewrite_integrity string enforced
I tried it 'query_rewrite_integrity' with 'trusted' as well .
View 7 Replies
View Related
Apr 3, 2012
One of our query is not using function based index, the required priv is granted to the user executing the query and also tables stats are gathered? what could be the reason for the query to not to pick the FBIndx? the table is a huge one having million of records, is it that CBO thinks that not picking FB indx is the best execution plan? let me know how can we make the query use the FB indx, also there is a restriction that we cannot force it using hints.
View 3 Replies
View Related
Jul 2, 2010
Using oracle 10g R2 on sun-solaris 10 (sparc-64) Well in the MIS system we have lot of ad-hoc queries coming up. We have proper indexing. Say an example which runs very slow;
SELECT GLKCO, GLDCT, GLDOC, GLDGJ, GLJELN, GLEXTL, GLPOST, GLICU, GLICUT, GLDICJ, GLDSYJ,
GLTICU, GLCO, GLANI, GLAM, GLAID, GLMCU, GLOBJ, GLSUB, GLSBL, GLSBLT, GLLT, GLPN, GLCTRY, GLFY, GLFQ,GLCRCD, GLCRR, GLHCRR, GLHDGJ, GLAA, GLU, GLUM, GLGLC, GLRE, GLEXA, GLEXR, GLUPMJ, GLUPMT, GLBCRC, GLCRRM, GLACR, GLAN8
FROM "PRODDTA"."F0911"
WHERE GLUPMJ <> 0
AND TO_DATE('1 JAN' || (19+substr( GLUPMJ , 1, 1)) || substr( GLUPMJ ,2,2)) + substr( GLUPMJ , 4, 3 ) -1 BETWEEN SYSDATE - 365 AND SYSDATE
[code]....
Here GLUPMJ already indexed so the second query returing an index scan but the first query does a FTS naturally.Now even if I plan to create a function based index on 'the bold highlighted' but how.
create index glupmj_idx on f0911(TO_DATE('1 JAN' || (19+substr( GLUPMJ , 1, 1)) || substr( GLUPMJ ,2,2)) + substr( GLUPMJ , 4, 3 ));..Error If I don't use a FBI my query will result in FTS.
1> how to create a FBI here in this case
2> In MIS systems where 'n' no of ad-hoc queries can come up, how to avoid FTS.
View 4 Replies
View Related
Nov 4, 2010
I have the following query with analytic function but wrong results on the last column COUNT.
1)I am getting the output order by b.sequence_no column . This is a must.
2)COUNT Column :
I don't want the total count based on thor column hence there is no point in grouping by that column. The actual requirement to achieve COUNT is:
2a -If in the next row, if either the THOR and LOC combination changes to a new value, then COUNT=1
(In other words, if it is different from the following row)
2b-If the values of THOR and LOC repeats in the following row, then the count should be the total of all those same value rows until the rows become different.
(In this case 2b-WHERE THE ROWS ARE SAME- also I only want to show these same rows only once. This is shown in the "MY REQUIRED OUTPUT) .
My present query:
select r.name REGION ,
p.name PT,
do.name DELOFF,
ro.name ROUTE,
[code]...
My incorrect output[PART OF DATA]:Quote:
REGIONPT DELOFF ROUTE THOR LOC SEQ COUNT
NAASNAAS MAYNOOTHMAYNOOTHR010 DUBLINRD CEL 1 1
NAASNAAS MAYNOOTHMAYNOOTHR010 NEWTOWNRD CEL 2 1
[code]...
My required output[PART OF DATA]-:Quote:
REGIONPT DELOFF ROUTE THOR LOC COUNT
NAASNAAS MAYNOOTHMAYNOOTHR010 DUBLINRD CEL 1
NAASNAAS MAYNOOTHMAYNOOTHR010 NEWTOWNRD CEL 1
NAASNAAS MAYNOOTHMAYNOOTHR010 PRIMHILL CEL 1
[code]...
NOTE :Count as 1 is correctly coming.But where there is same rows and I want to take the total count on them, I am not getting.
View 9 Replies
View Related
Oct 24, 2013
Oracle 11g databaseidval1val2100a110b120c200a220b
WITH input AS
(SELECT 1 id
[Code].....
input; Output:idval1val2assigned_number100a0110b0120c2200a0220b1 The dense numbering sequence should be assigned to each row based on id and val1 column. For a given Id, the numbering only starts after val1 > 1 till then the assigned_number will be zero.
View 1 Replies
View Related
Jun 27, 2013
It is not possible to run SHRINK SPACE against a table with a function based index. This is documented, and I've tested on the current release. I've reverse engineered it a bit, and the issue is in fact that you cannot SHRINK SPACE if there is an index on a virtual column:SQL> SQL> create table t1(c1 number, c2 as (c1*2)) segment creation immediate;
Table created.
SQL> alter table t1 enable row movement;
Table altered.
SQL> alter table t1 shrink space;
Table altered.
SQL> create index i1 on t1(c2);
Index created.
SQL> alter table t1 shrink space;
alter table t1 shrink space
ERROR at line 1: ORA-10631: SHRINK clause should not be specified for this object.
View 2 Replies
View Related
Sep 10, 2012
RDBMS - 11.1.0.7, I it possible to convert indexes of a non-partitioned table to hash partitioned indexes by retaining table as non-partitioned?
If yes, is this what it is Creating a Hash-Partitioned Global Index - can be created for partitioned and non-partitioned tables?
View 7 Replies
View Related
May 9, 2011
this is just a generic question. If a table has multiple Indexes on it say a table of 20 columns where 8 columns have indexes on it (each columns out of the 8 has an index on it and out of which three columns contain unique indexes on it).
If i run a query on this table where only two columns are specified in the where clause are the remaining 6 indexes on the table scanned during query execution.
View 1 Replies
View Related
Oct 9, 2012
on 11g R2 on Win 2008
How to find ddl for any indexes built on MY_VW ?
View 6 Replies
View Related
Aug 15, 2011
If I have owner, table_name is there a query I can issue that will tell me if I have to add the "update global indexes" clause when dropping a partition from a table?
View 1 Replies
View Related
Mar 16, 2011
Why we can create indexes only on materialized view and not on normal views?
View 8 Replies
View Related
Sep 1, 2013
Say we have an employee(id_emp) table with a primary key on id_emp. We have also some history tables emp_stuff with columns say (id_emp, dat_event, some_stuff) with primary key id_emp, dat_event.
This means that we have a unique index on (id_emp,dat_event). We also have a foreign key id_emp that references employee(id_emp). When we update id_emp on employee, we still have a lock on emp_stuff. According to this (end of the page) :
Quote:So, in short, with releases prior to Oracle Database 11g Release 1, you will want an index on the foreign key of the child table if you do any of the following:
Update the parent table primary key
Delete from the parent table
Merge into the parent table
So is id_emp in emp_stuff considered as indexed (through the unique index of the primary key) or do we have to add an explicit index
like this CREATE INDEX emp_stuff ON emp_stuff(id_emp) to avoide child table locks?
View 33 Replies
View Related
Mar 16, 2010
Lot of my tables are just for join purpose , a table with just with two columns both FK , I did not add any composite PK to this table, lot my queries uses this table , because it does not have composite PK will the query be slow ? what I have to do to increase performance querying with such tables ?
View 5 Replies
View Related
Jul 12, 2012
How many different types of indexes we have in oracle?
View 2 Replies
View Related
Feb 22, 2013
Using Oracle 11.2.0.3
We are evaluating partition strategies with view to achieving performance gains in reporting in particular. How efficient are partitioned indexes in this regard e.g.
just partitioned indexes on an un partitioned table.
One large fact table with durrogate keys on which have bitmpa indexes which link to unique key in associated dimensions. Considering partitioning the bitmap index which links to the largest dimension and similarly partition the dimension key on largest dimension.
View 5 Replies
View Related
Jan 16, 2013
currently i am using below version
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
PL/SQL Release 11.2.0.1.0 - Production
CORE 11.2.0.1.0 Production
TNS for 32-bit Windows: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
{CODE}
here is my query to find out the list of indexes and positions in a single schema.SELECT
user_indexes.TABLE_NAME||CHR(9)||
user_indexes.INDEX_NAME||CHR(9)||
TRIM(user_ind_columns.COLUMN_NAME)||CHR(9)||
user_ind_columns.column_position ||CHR(9)||
[code]...
i am trying to spool the output to .txt file. in textfile the output should be in below format :
Table_name Index_name column_names
---------------- ---------------- ------------------
ACS_TEST ACS_TEST_IDX COL1,COL2
C_COLLEGE INX_COLL STUDENT_ID,FIRST_NAME,LAST_NAME,DEPT_ID
Note : Based on the position value the column name have to be placed.
View 2 Replies
View Related
Jan 15, 2013
I am trying to find out database name for the unusable indexes thru the query; I am using dba_indexes for the index name but not sure which view I need to join with to find the db name.
View 11 Replies
View Related
Jul 31, 2013
How can i check that indexes need rebuild?
View 6 Replies
View Related
Dec 13, 2012
Does size (number of rows) of table and corresponding indexes have influence on INSERT operations (bigger table - slower insert)?
I supposed that if select returns the same rows in small and big table, there will be no difference in performance?
View 4 Replies
View Related
Oct 28, 2010
A basic select and group by query I am optimising for my Database course has returned results that indicate it will perform better on a clustered index when returning a smaller number of rows (5% of the largest table) and on a hash clustered index when returning higher volumes (50% and 80%). I understand that it is possible to use more than one index type on a table to improve performance, but I am struggling to understand how I might establish a hash cluster and a cluster on the same table? and then use hints to drive the query down one access path or the other.
Site admin - this site is a very useful resource.
View 5 Replies
View Related
Jan 18, 2011
I want drop some old partitions from big table but this will not increase free space on disk. So I want to move table with indexes to anothers tablespaces. What is the fastest way to do that? ALTER TABLE ... MOVE TABLESPACE ...? CTAS ? Or something else?
View 4 Replies
View Related
Jul 18, 2013
I have a few dimension tables with surrogate keys and a fact table with foreign keys on columns referring to the dimension table. I want to create primary keys on the dimension tables and foreign keys on the fact table, but with minimal overhead of constraint validation when loading the data.
Other than bitmap indexes on the FK columns on the fact table, I also want to create a bitmap join index on the fact table joined to the dimension table on a handful of dimension columns.
Which is the best suited constraint definition? Only RELY, or RELY + DISABLE, or RELY + DISABLE + NOVALIDATE, or RELY + NOVALIDATE, or any other?
View 9 Replies
View Related
Jan 9, 2008
I have created materiaized view
Create Materialized View table_name
Tablespace FG_Report
Build Immediate Refresh Force
Start with SYSDATE next SYSDATE+5/1440
As Select * from table_name@dblink;
after creating, i don't see indexes on the the materialized view created. where as in actual table we have indexes..
Can we replicate indexes along with Materialized views?
View 1 Replies
View Related
Oct 3, 2012
I have a task to create a procedure that disables (particular) partitioned indexes and REBUILD after ETL load.
Developers wants 3 parameters for the procedure:
1) TABLE_OWNER2) TABLE_NAME3) TRANSACTION_DATE = 13-JUN-12
And here is what I have done. I have created a procedure that takes 3 input parameters, please see the attached script:
1) TABLE_OWNER 2) TABLE_NAME 3) PARTITION_NAME - requires to query the particular partition to get the partition name
a situation where they will input dates as the partition was on a DATE column, now my challenge is how to incorporate this into the procedure to accept DATE as an input which will require one to query the particular table to get dates.I thought of using (HIGH_VALUE - 1) to get the dates from ALL_IND_PARTITIONS.
View 2 Replies
View Related
