Secondary Index vs Secondary Indices

Hi All,
In the earlier version already we have the primary index,secondary indexes,But now iam going through the enhancements in NW 7.0 In this they mentioned Secondary indices as the new enhancement with NW 7.0,I know how to create the Secondary indices ,But i am getting the conffusion between secondary indexes (already we have) and the new Secondary Indices,So please could any one elobarate this or atleast URL'S which are relavant to this topic,It would be very help full to me.
Thank you..
Srihasa

new index are just different at workbench level, but are the same at database level. You may assign them to a Y or Z package (instead of the sap package, it was seen as a modification of the standard). They also have a dedicated object directory entry (R3TR XINX). http://help.sap.com/saphelp_erp2005vp/helpdata/EN/85/685a41cdbf8047e10000000a1550b0/frameset.htm
[Note 1257033 - Cookbook: Modification/enhancement for standard SAP system|http://service.sap.com/sap/support/notes/1257033]

Similar Messages

Secondary index vs secondary db

I would like to be able to search against 2 fields. One is timestamp field, the other is name. So, I would like to search like within certain time range, all the records with name=XXX. Is it better to define 2 keys in my callback or to have two secondary db with one key each and then join them?
What is a better way?
Also, I can set for time_stamp > 123 with SET_DB_RANGE, but how can I search for time_stamp> 123 and time_stamp < 444?

new index are just different at workbench level, but are the same at database level. You may assign them to a Y or Z package (instead of the sap package, it was seen as a modification of the standard). They also have a dedicated object directory entry (R3TR XINX). http://help.sap.com/saphelp_erp2005vp/helpdata/EN/85/685a41cdbf8047e10000000a1550b0/frameset.htm
[Note 1257033 - Cookbook: Modification/enhancement for standard SAP system|http://service.sap.com/sap/support/notes/1257033]

Data deletion on primary index and secondary index

Hello, I have a question regarding data deletion in BDB-JE.
Suppose I have an Entity class which has a primary index and a secondary index, the secondary key does not have outer related entity. So when I want to delete this entity, is it correct we only need to remove the entity from primary index? or I also need to do it for secondary index or just remove it from secondary index and internally BDB_JE will remove it from primary index?
Thanks
Anfernee

You can delete an Entity using the delete method for primary index or the secondary index. When an entity is deleted, secondary index records are automatically deleted. The primary and secondary indices are always kept in sync.
--mark

What are the disadvantages of secondary index

Hi all,
Can anybody tell me what are the disadvantages of creating secondary index?
Also tell me what are the precautions should be taken to create a secondary index?

Hi Vinil,
You can search on SCN with the same subject... you will get lots of threads discussed on it...
Still for your reference...
secondary indices use disk space, not memory space. They are only in memory when they are used. Disk space is roughly width times number of records, can be GBs.
Main disadvantages are:
+ indexes are updated when table is changed, i.e. the additional index makes other operations slower. You must check the importance of your application, if it is much lower than the standard usage than you can not create a secondary index.
+ Secondary indices can confuse the database optimzer, especially if you use field which appear also in other indices. DB calculates usefulness of different indices by some assumptions (check other sources for details), if two indices are similar, than the assumptions can lead to wrong decisions. Your new index can be used for other statements, even when it is not optimal there. Result your index causes problems somewhere else!
Hope it will solve your problem..
Thanks & Regards
ilesh 24x7
ilesh Nandaniya

Database tableAUFM hitting is taking much time even secondary index created

Hi Friends,
   There is report for Goods movement rel. to Service orders + Acc.indicator.
   We have two testing Systems(EBQ for developer and PEQ from client side).
   EBQ system contains replica of PEQ every month.
   This report is not taking much time in EBQ.But it is taking much time in PEQ.For the selection criteria I have given,both systems have same data(Getting same output).
The report has the follwoing fields on the selection criteria:
A_MJAHR     Material Doc. Year (Mandatory)
S_BLDAT     Document Date(Optional)
S_BUDAT     Posting Date(Optional)
S_LGORT     Storage Location(Optional)
S_MATNR     Material(Optional)
S_MBLNR     Material Documen(Optional)t
S_WERKS     Plant(Optional)
Client not agrrying to make Material Documen as Mandatory.
The main (first) table hit is on AUFM table .As there are non-key fileds as well in where condition,We have cretaed a secondary index as well for AUFM table on the following fields:
BLDAT
BUDAT
MATNR
WERKS
LGORT
Even then also ,in PEQ sytem the report is taking very long time ,Some times not even getting the ALV output.
What can be done to get teh report executed very fast.
<removed by moderator>
The part of report Soure code is as below:
<long code part removed by moderator>
Thanks and Regards,
Rama chary.P
Moderator message: please stay within the 2500 character limit to preserve formatting, only post relevant portions of the code, also please read the following sticky thread before posting.
Please Read before Posting in the Performance and Tuning Forum
locked by: Thomas Zloch on Sep 15, 2010 11:40 AM

Hi Friends,
   There is report for Goods movement rel. to Service orders + Acc.indicator.
   We have two testing Systems(EBQ for developer and PEQ from client side).
   EBQ system contains replica of PEQ every month.
   This report is not taking much time in EBQ.But it is taking much time in PEQ.For the selection criteria I have given,both systems have same data(Getting same output).
The report has the follwoing fields on the selection criteria:
A_MJAHR     Material Doc. Year (Mandatory)
S_BLDAT     Document Date(Optional)
S_BUDAT     Posting Date(Optional)
S_LGORT     Storage Location(Optional)
S_MATNR     Material(Optional)
S_MBLNR     Material Documen(Optional)t
S_WERKS     Plant(Optional)
Client not agrrying to make Material Documen as Mandatory.
The main (first) table hit is on AUFM table .As there are non-key fileds as well in where condition,We have cretaed a secondary index as well for AUFM table on the following fields:
BLDAT
BUDAT
MATNR
WERKS
LGORT
Even then also ,in PEQ sytem the report is taking very long time ,Some times not even getting the ALV output.
What can be done to get teh report executed very fast.
<removed by moderator>
The part of report Soure code is as below:
<long code part removed by moderator>
Thanks and Regards,
Rama chary.P
Moderator message: please stay within the 2500 character limit to preserve formatting, only post relevant portions of the code, also please read the following sticky thread before posting.
Please Read before Posting in the Performance and Tuning Forum
locked by: Thomas Zloch on Sep 15, 2010 11:40 AM

Transaction DB02 = Missing Tables and Indexes shows under Secondary indexes from package $tmp

Hi SAP Gurus,
I noticed on our SAP business warehouse (BW) system (NetWeaver 7.0 based on AIX/Oracle 11g) in transaction DB02 => Diagnostics => Missing Tables and Indexes under Secondary indexes, 26 indexes, in package $tmp:
The indexes are defined, but they don't have been created on the database.
When I try to create them via the database tool, I am getting the warning:
Does the warning raise up, because they where defined in the $tmp package?
I was looking in SAP notes for a solution for this "warning" concerning the /BIC/F-Indexes but I didn't found yet anything helpful ...
Thanks for your help and ideas ...
Best regards
Carlos

Hi Carlos,
These are secondary indexes created during process chains in BI to improvise performance.
You may refer below SCN blogs on creation of these indices in BI.
Secondary Index - Improving DSO insert/read performance
How to Create Secondary Index on DSO in SAP BW
Hope this helps.
Regards,
Deepak Kori

Missing secondary indexes

Hello Gurus,
Hope you are doing good ! I have few missing secondary indexes. I have corrected them in rsrv with the correct error option but still most of them seem to be back in DB02. Warnings have occured for few cubes being : Oracle:Index/BI0/SDOC_NUMBER~0 has possible degenareted.
I checked in the process chains but the indexes are successfully built. Any sugestions pls let me know.
Kind Regards,
Sunitha

Hi Sunitha,
Try checking these indices from cube/DSO Performance tab and try with the repair option available there.
Sometimes, it might be possible to the tablespace problem to build the indices. Check those too also from DB02.
Regards,
Srinivas.

Three questions about the creation of secondary indexes in ODS design mode

1. When we right click the Indexes folder in ODS design to select Create to create the Index folder 010, a small window pops up with a check box called "Unique", do we have to check this checkbox to create folder 010?
2. If we would like to include 3 InfoObjects into the secondary indexes, then how many folders we need to create? Need to create 3 folders like 010, 020, and 030 and place the 3 InfoObj. into the 3 folder respectively or create only one folder 010 and place all the 3 InfoObj. into this one folder 010?
3. In SAP documentation titled "BW Performance Tuning" about the Indices, it says "If the (uncompressed) F fact table is small, it is usually faster to drop the secondary (bitmap) indices before the load and build them up after the load"
Someone here says secondary index is only for ODS other than for cubes, but from the above statement, F fact table is related to cubes, then how to explain it? Also the above statement is talking above the variant in process chain that when you bring in a variant to load data to cube, then the drop index and generate index variants will be automatically created, does it refer to this? And what's bitmap index?
Thanks in advance and we will continue to give you reward points!

Hi Kevin,
Cube has Secondary index's. The index's that we find in the Manage of the Cube are the Secondary Index's. Please check the following link for more information.
http://help.sap.com/saphelp_erp2004/helpdata/en/80/1a6473e07211d2acb80000e829fbfe/frameset.htm
Also, to know about Unique indexes, use the following link
http://help.sap.com/saphelp_erp2004/helpdata/en/9b/c743f5b40711d194f900a0c929b3c3/frameset.htm
"The indexes displayed are the secondary indexes of the F and E fact tables for the InfoCube. The primary indexes and those defined by the user are not displayed. " (SAP help).
This should answer your questions.
Regards,
Praveen.

Maximum Number fields in a secondary index key

Hello All,
We created a secondary index on BSIS which we had to drop as system was hung up. My question is how many fileds SAP recommends in a secondary index key? Ours had 6 keys including mandt.
Thanks

Hi Sameer,
There is no real specification in number of fields for an index as fas as i know. Definitely 6 fields is allowed for a secondary
index.But it really matters with the number of secondary indices. So dont create too many secondary index for a single table.
Try to use other optimization techniques in the programming instead of creating secondary index.
//Kothand

Missing secondary index after TDMS data deletion

We have done a TDTIM transfer to a single client system. The deletion technique used by TDMS is Drop-insert technique.
During our initial analysis, we found that many of the secondary indices are not re-created by TDMS at database level. For many few tables the secondary indices are re-created at the database level.
Will TDMS delete and re-create the secondary index for re-created (droped & created) tables during data deletion in receiver system ?
Why did TDMS re-create secondary indices for few tables and why it didnot re-create secondary indices for few other tables?
Thanks
Praven

Indexes are deleted from the receiver only in cases when they were not present at the DB level in the receiver system
prior to TDMS run. This is to avoid any kind of error/exceptions when records are inserted into the table.
You need to create these indexes manually.
In order to do so, you can follow the steps below:
1. Execute transaction DB02.
2. Select the button "missing indexes". A list of 1091 is shown
3. Place the cursor on the line "secondary indexes" and hit F9
4. Now hit "create on DB".
5. A popup will ask if you want to do a mass select. Press "Yes"
6. A further Popup will then ask for background processing. Say "Yes".
Best Regards,
Rupam

The fact table of InfoCube 0OPA_C11 is missing 2 secondary indexes

Hello experts,
in RSRV i got the above mentioned message for my InfoCube 0OPA_C11. Before I tried to delete, repair and build up my indices in performance tab of the InfoCube.
I followed SAP Note '401242 - Problems with InfoCube or aggregate indexes'.
-> SAP_INFOCUBE_INDEXES_REPAIR repaired indexes and show no further problem, but problem still exists, in performance tab light is red and RSRV brings same message.
Does someone have any idea what further I can do?
Best regards,
Peter

Peter, refer to note 928037, it's FAQ about MaxDB indexes. I gave it a quick reading and I believe the answer to this issue lies beneath this doc! There are ways to check consistency of individual index, bad indexes and ways of eliminating them.
Also, refer to the below blog. Check the status of the secondary index in this case. I suspect they are bad or missing. There are ways to recreate them. Keep your basis guys in the loop.
http://wiki.sdn.sap.com/wiki/display/MaxDB/MaxDBIndex%28Secondary+Key%29
Hope this helps.
Edited by: Mann Krishna on Sep 10, 2010 3:50 PM

Reg. Secondary indexes

HI,
While using Secondary index,
If I am having a table and I set fields f3,f4,f5 as secondary index1, f6,f7,f8 as secondary index2, f9,f10,f11 as secondary index3 for using them for selecting fields for 3 different programs respectively.
Here i have some doubts---
For doing like this, will the table be affected performance wise? if yes how? Then what will be solution for using those fields?
pls suggest.
thanks
points will be awarded

Hi everyone,
I agree with Rob, in the sense I would not create any secondary indices on standard tables, if possible (unless recommended by a SAP note).
In Z tables -> well, the performance of SELECT statements for those fields is improved, for sure. But every time you want to INSERT/UPDATE/DELETE on the table, SAP takes more time to do the operation, because it has to populate the data in the table, and also update the indices. So be careful and check the performance on your test systems before transporting to productive environment.
I hope it helps. Best regards,
Alvaro

Question about Berkeley DB Primary Index/Secondary Index in DPL package

We are using DPL package for BDB access.
My question is about memory consumption by Primary or Secondary Index. We are using BDB only for Read Purposes
e.g. Let's say if we are using BDB to store 250GB of Raw Data (which will translate to .jdb files which will have all indexes). Each box is having around 32GB memory.
1) So when we call method store.getPrimaryIndex(....) or Create Secondary Index; how much size these Indexes will take up in memory ?
2) Is it advisable to keep these Indexes in memory all the time ?
Thanks,

I have a couple caveats to add on DbCacheSize.
1) It is an estimate, and for ordinary databases (without duplicate keys) is an upper bound.
2) For databases with duplicate keys (in the DPL these are MANY_TO_ONE and MANY_TO_MANY secondary indices), it is incorrect and can be used as a lower bound.
So it gives only a rough estimate. If you need an accurate number, write a DPL-based program that creates a realistic data set and look at EnvironmentStats.getCacheTotalBytes to see how much memory is used prior to any eviction occurring, which is indicated byEnvironmentStats.getNEvictPasses. Use a machine that has as much memory as possible, set the Java heap size and the JE cache size to the maximum possible, and create the data set as close as possible to the size you expect in production.
2) Is it advisable to keep these Indexes in memory all the time ?Yes. The FAQ has multiple entries on this topic in the performance section.
--mark

Secondary Index on ODS Change Table

Hi All,
We have a process that does a lookup to the change table /bic/XXXX40 in the update rules while loading the ODS. We are having performance problems that can be resolved by putting a secondary index on the change table. We are able to create the index in the Dev env using SE11, but we can't put it in a package other than $TMP. Putting a secondary index on the ODS in the normal way didn't put the index on the change table so that doesn't help us.
Any ideas on how we can get our new index into a package that we can transport?
Thanks in advance!

Just echoing Jorge's post - you'll need to open Prod and create it there, same is if you were creating secondary indices on master data tables or dimension tables, since the wkbench doesn't support creating indices on them either.
PS.
Put yourself on the SDN world map (http://sdn.idizaai.be/sdn_world/sdn_world.html) and earn 25 points.
Spread the wor(l)d!

Can a replica node have secondary indexes the master does not?

In a JE replication group, is it possible to instantiate a replica (non-master) node that includes additional secondary indices that the master and the other replicas do not have? I would like to have this replica node optimized for performing fast searches on the additional indexes. Previously, all my nodes have had the exact same schema with only a single, primary index. Certainly I could add the secondary indexes on all the nodes, including the master, but the other nodes won't benefit from the add'l indexes as no such searches are expected to be performed on those nodes.

Hi,
No, this is not currently supported. Secondaries must be created on the master as usual and will be replicated to all nodes. However, if secondaries are read frequently on a particular node, they are more likely to stay in cache on that node, or at least more so than on other nodes. So it still may be beneficial to service read requests for secondaries on a subset of nodes. This is a special case of the more general approach where read requests are balanced among nodes according to some form of data partitioning.
The ability to store secondary indexes only on particular nodes would require several new features and is not currently planned:
- ability to have non-replicated databases in a replicated environment
- triggers on the replica so that secondaries can be maintained
- automatic re-creation of indexes when a node is restored from scratch
--mark

Secondary Index vs Secondary Indices

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