1. Where do I find the MaxDB documentation?
See Note 767598 for information about the location of the MaxDB documentation.
If you are searching for a specific term in the MaxDB documentation and you do not know which guide contains the relevant information, we recommend that you use the MaxDB glossary in the documentation. The terms are sorted in alphabetical order. If you do not find the required term in the glossary, open a customer message on SAP Service Marketplace for the BC-DB-SDB component so that the term can be included in the glossary.
2. For which component must I open a customer message if I have problems with the MaxDB database?
BC-DB-SDB: For problems with the MaxDB OLTP database or a content server.
BC-DB-SDB-CCM: For problems with the MaxDB transactions DB12,DB13,DB50 ,DB59 RZ20,RZ21,ST04
BC-DB-SDB-INS: For problems with the MaxDB installation.
BC-DB-SDB-UPG: For problems with the MaxDB upgrade.
BW-SYS-DB-SDB: For problems in the Business Warehouse system with MaxDB.
3. What MaxDB versions are currently supported?
This information is available in the Product Availability Matrix (PAM) at
http://service.sap.com/pam
Currently, you can use MaxDB Version 7.3, 7.4, 7.5 and 7.6 in live SAP Systems.
For information about the end of maintenance, see the following notes:
SAP DB Version 6.1 and 6.2.8: Note 178377
SAP DB Version 6.2.9: Note 197492
SAP DB Version 6.2.10: Note 422058
SAP DB Version 7.1: Note 446117
SAP DB Version 7.4: Note 832863
4. How can I interpret the MaxDB version string?
Importance for Version 7.5 or lower, for example kernel version 7.5:
7.5.0 BUILD 026-123-094-430
Major Number: 7
Minor Number: 5
Correction Level: 0
Build Number: 026
Support Information: 123-094-430
The interpretation of the MaxDB/liveCache version string changes with MaxDB Version 7.6.
Importance for Version 7.6 or higher, for example kernel version 7.6:
7.6.01 BUILD 020-123-115-206
Major Number: 7
Minor Number: 6
Support Package: 01.
Patch Level:020 (Build Number)
Support Information: 123-115-206
As of Version 7.6, a model was introduced with Support Packages and patch levels.
Support Packages:
- are created on a quarterly basis (approximately)
- in addition to the error corrections, Support Packages also include new functions (change requests).
Patch levels:
- are created more often than Support Packages and according to requirements (error situation),
- only high priority errors are corrected,
- corrections for delivered versions always result in a new patch level number.
5. What information is relevant for support in the last nine characters of the version string after the build number?
The last nine characters of the MaxDB version string contain additional information for Support.
For example: 7.6.01 BUILD 020-123-115-206
After the patch level (for example, 020), the string specifies the release status (for example, 1), the make status (for example, 2) and the usage (for example, 3).
a) The release status specifies whether the used version is a test system or development system (value=0), or whether it is a system that can be used productively (value=1).
b) The make status specifies in which delivery status the created version is contained.
-> Value = 0 is a version that was created on the basis of a delivery level (DEV). Customers should not use such versions in productive environments.
-> Value = 1 is a version that was created on the basis of a correction level (COR). Customers should not use such versions in productive environments.
-> Value = 2 is a version that was created on the basis of an official delivery level (RAMP). As a rule, this should be the case in the productive system.
-> Value = 3 is a Support Package.
-> Value = 4 is a special analysis level that you should only use for analysis purposes. Customers should not use such versions in productive environments.
c) The usage specifies for which system environments this version was created.
-> Value = 0 there is no special usage
-> Value = 1 this version was only created for OLTP systems.
-> Value = 2 this version was only created for liveCache.
-> Value = 3 this version was created for all system types and can be used anywhere.
The following six characters (for example 115-206) are significant for Make Factory colleagues. They specify the change list number. This number uniquely identifies the underlying module amount and module instance of the MaxDB/liveCache version.
6. What combinations of MaxDB, R/3 system and operating system may I use?
See the following notes:
If you use SAP kernel 3.0x or 3.1.x: Note 23870
If you use SAP kernel 4.0x and 4.5x: Note 85841
If you use SAP kernel 4.6x: Note 156551
If you use SAP kernel 6.x: Notes 727683 and 407320
The latest overview of MaxDB, R/3 system and operating system combinations is contained in the PAM which is located on SAP Service Marketplace under the PAM alias:
http://service.sap.com/pam
Consider our recommendation in Note 1013441 that you should use 32-bit platforms with MaxDB.
7. Can MaxDB run in a virtual environment?
For more information about this, see Note 1142243 and the notes referenced in that note.
8. Where do I find information about new MaxDB features?
Refer to the following notes that contain MaxDB feature lists:
MaxDB Version 7.3: Note 685873
MaxDB Version 7.4.03: Note 710165
MaxDB Version 7.5: Note 710166
MaxDB Version 7.6: Note 806690
9. What interfaces are supported by MaxDB?
ODBC (3.5.1), JDBC (2.0/3.0), SQL Database Connectivity (SQLDBC).
For more information, see the interfaces guide in the MaxDB documentation (see Note 767598).
10. Are there any limits on the size and the number of users of a MaxDB database?
No, there are no limits.
11. Must I reorganize a MaxDB database?
No, due to the shadow memory concept and the dynamic storage management, reorganization is not necessary.
12. Where do I find more information about MaxDB administration?
For more information about MaxDB administration, see the FAQ in Note 846890.
13. Where do I get the MaxDB CDs for installing or upgrading the database?
To install MaxDB software, use only the MaxDB RDBMS CDs delivered by SAP. CDs that you have obtained directly from MySQL, or software levels downloaded from the MySQL page must not be used in the SAP environment.
For example, you can order the RDBMS CDs by opening a message on component XX-SER-SWFL-SHIP. It is important that you correctly specify the database release and operating system.
14. What must I consider if I want to migrate with a 40B or 45B system to MaxDB?
SAP Versions 40B and 45B go out of service at the end of 2006.
You should carry out a migration to MaxDB on Version 7.5. For more information, see Note 715701.
You must have carried out a text migration. You must confirm the success of this test migration in a customer message before you can carry out the productive migration.
15. How do I install a MaxDB kernel patch?
Note 498036 contains basic information, and specifies which note you should use to import a specific patch.
16. Where can I download the MaxDB software versions?
You can download released MaxDB software patches from SAP Service Marketplace:
http://service.sap.com/swdc
In the SAP environment, do not use any versions that you have downloaded from the SQL. These versions have not been tested by SAP and, therefore, should not be used.
17. Where do I find information about the MaxDB upgrade?
The MaxDB upgrade operations are described in the MaxDB upgrade guides for the relevant MaxDB target releases and operating systems, and the guides are located on SAP Service Marketplace under the quick link "instguides":
http://service.sap.com/instguides
-> Other Documentation
-> Database Upgrades
-> MaxDB or SAP DB
The guides also contain all notes that are required for the upgrade.
18. How do I install the MaxDB client software?
Note 649814 describes the installation of the MaxDB client software on a Web application server.
19. How do I install a DBADASLIB patch?
Note 325402 describes the upgrade of a dbadaslib library.
20. How can I uninstall the database software?
If you want to delete a MaxDB database installation, you must use the SDBUNINST uninstallation tool as described in Note 599129.
Do NOT delete the directories only, since the installations are registered in the MaxDB install registry on both Windows and UNIX. You must remover the relevant installation from the MaxDB install registry with the SDBUNINST tool.
21. How large should I configure the data volumes of a MaxDB database?
It is not only the size of a data volume that is important for system performance, but also the number of volumes. The number of volumes determines the scaling of the I/O. Depending on the number of configured volumes, MaxDB configures threads (_IOPROCS_PER_DEV), which are responsible for the I/O.
The number of threads for each volume is configured using the _IOPROCS_PER_DEV parameter. We recommend the following values: 2 (UNIX), 1 (WINDOWS)
Therefore, subsequent I/O operations to a volume are distributed to several threads.
You should increase the number of I/O threads for each volume if the database has been configured with a small number of data volumes, but the I/O system allows more parallel I/O.
However, it is advantageous to use an appropriately large amount of data volumes, because the data writer and user tasks must then check less frequently if an I/O queue is already busy.
Too many data volumes increase the number of threads, and can approach the limits of the operating system resources in this way.
We recommend the following calculation formula: Use the 'square root of the system size in GB, rounded up' to specify the size of the MaxDB data volumes.
For example:
10 GB: 4 Volumes
50 GB: 8 Volumes
100 GB: 10 Volumes
200 GB: 15 Volumes
500 GB: 23 Volumes
1 TB: 32 Volumes
22. Should I create MaxDB volumes on raw devices or files?
A raw device is a hard disk or part of a hard disk that is not managed by the operating system. On Unix or Linux, you can configure raw device volumes for database instances. SAP recommends raw devices for data volumes and log volumes on Unix. The database system can usually access raw devices faster than files. In addition, the operating system can usually boot raw devices faster, because it must not check the consistency of the file system.
23. Where do I find information about configuring MaxDB volumes of file type?
The speed, with which the database system can read data from the volumes and can write data to the volumes, greatly influences the performance of the database instance. To achieve good performance when the database instance is operating later, see Note 993848 (Direct I/O mount options for LiveCache/MaxDB) for information about creating and configuring volumes of file type.
24. How should I set the MAXCPU parameter for DUAL Core CPUs?
Since dual core CPUs actually have 2 cores with separate execution units (a separate L1 cache and sometimes even a separate L2 cache), you should use the doubled number of CPUs as a basis when you calculate MAXCPU.
MAXCPU =
To set the MAXCPU parameter, see the FAQ Note 936058 MAXDB.
25. Does MaxDB support clusters for failover on UNIX or Linux?
Yes. The agents for the relevant cluster implementations give you the manufacturers of the failover solutions. For Linux, a solution is available from www.steeleye.com .
26. Where can I find information on MaxDB High Availability?
See Note 952783
27. How do I install a MaxDB database in a Microsoft cluster?
Note 576063 describes the installation of a MaxDB database in a Microsoft cluster.
The Microsoft cluster installation with SAPinst is described in Note 760137 for 6.20-based products.
Note 728879 contains the descriptions for a few 6.40 Basis products.
As of NetWeaver 04, Service Release 1, the cluster installation and the installation guide are contained on the installation CD.
28. What should I bear in mind when I upgrade MaxDB on a Microsoft cluster?
Currently, no automatic upgrade exists that takes the MSCS cluster environment into account. This means that you need to carry out some steps manually. Notes 508979, 843560 or 912246 describe which steps you must carry out when you upgrade MaxDB on an MSCS cluster.
29. Can I use the split-mirror and snapshot functions available in third-party storage systems with MaxDB?
Yes, see Note 371247 for more information.
30. What log files are available for MaxDB?
A list of the MaxDB log files and their functions
is contained in the MaxDB documentation (see Note 767598). Search the glossary for the term
"Log file".
31. Where do I find the MaxDB log files?
The MaxDB log files are stored in the MaxDB directory (the RUNDIRECTORY).
32. How can I locate the run directory?
The location of the RUNDIRECTORY is determined during the database installation with the MaxDB RUNDIRECTORY kernel parameter. The dbmcli command, param_directget RUNDIRECTORY, returns the path to the run directory.
33. Where do I find explanations for MaxDB error codes?
The MaxDB messages guide contains a description of the MaxDB error codes. See Note 767598 for the location of the messages guide.
34. Where do I find the MaxDB parameter file?
The MaxDB parameter file is stored in the RUNDIRECTORY under the name of . You can only retrieve the file with a database tool (DBMCLI or DBMGUI).
35. Why do changes to the MaxDB parameter file not become active immediately?
Changes to the MaxDB parameter file only become active after you have stopped (offline) and restarted the MaxDB database.
36. Can I change the MaxDB parameters online?
In emergencies, some database parameters can also be changed online by SAP MaxDB Support. Customers should only use this option after prior consultation with SAP Support.
As of MaxDB Version 7.6, database parameters that do not determine memory sizes or the number of threads used can be changed online and activated immediately.
SAP employees may refer to Note 817934 for a description of the required procedure.
37. What are the recommended parameters for MaxDB?
The following notes contain recommendations for parameter settings for the relevant MaxDB versions:
MaxDB Version 7.2: Note 559237
MaxDB Version 7.5: Note 767635
MaxDB Version 7.6: Note 814704
38. What is MaxDB load balancing?
For more information, see Note 695721.
39. How do I make a MaxDB system copy?
For information about system copies, see the following notes:
Note 129352: Homogeneous system copy with MaxDB (SAP DB)
Note 489615: SAP DB or liveCache system copies via remote pipe
Note 371247: SAP DB and "Split-Mirror" techniques
If you use database Version 7.3, see also Note 421637.
40. Why are there so many VSERVER processes?
On Linux systems without NPTL (Native Posix Thread Library), every thread is simulated by a clone process. Therefore, the process list may contain several MaxDB processes with the same name.
41. Can I execute transports between databases of different releases?
Since the TP and R3TRANS transport tools work with a database-independent data format, you can execute transports between databases with different MaxDB versions without problems.
42. Where do I find information about the external backup tools supported by MaxDB?
Information about the external backup tools supported by MaxDB is contained in the installation guide of the MaxDB documentation (see Note 767598).
In addition, see Note 119863.
43. What performance analysis tools are available for MaxDB?
For more information, see Note 725489 . The note briefly describes the database analyzer and the command monitor. For more information about the database analyzer, see also Note 530394.
44. What do I do if the log area is full?
For more information, see Note 869267.
45. What do I do if the MaxDB database is full?
If the database is full, it stops until you have added a new volume (ADD Volume/Data Devspace) to MaxDB. For more information, see also Note 846890 FAQ: MaxDB Administration.
46. Where do I find information about hot standbys?
The MaxDB documentation (see Note 767598) contains information about hot standbys. Search the glossary for the term "Hot standby".
47. What effects does a change of the system time (for example, from daylight saving time to standard time) have on the MaxDB database?
The MaxDB kernel works with the local time. When you change to daylight saving time, you do not have to change the time manually at database level.
If a time interval occurs twice as the result of a time change, the system cannot determine at which of the two identical points of time it should stop when you perform a point-in-time recovery with an end time in the duplicate interval. In this case, you cannot perform the recovery with a target time that is located in the second interval.
If you wanted to execute a point-in-time recovery at the second point of time, you would have to work with the IO sequence number. However, a function for easy retrieval of the IO sequence number from the log is currently not available in the MaxDB versions available. (PTS: 1134130)
Problems do not occur during the recovery if you execute a Save Data during a time change, which means that the start time of the backup is later than the end time, and that subsequent log backups may be executed before the backup.
MaxDB databases do not use time stamps with Restore Data and Restore Log, but work with logical log page numbers. The backup has the information about what changes up to which log page number are already contained in the data area in the backup.
48. The standard installation does not include the MaxDB Web Tools. How can I get the MaxDB Web Tools?
See Note 856940.
49. How do I install SQL Studio and the database manager GUI?
See Note 386714.
50. What training does SAP offer for MaxDB?
SAP provides the following training on the subject of the MaxDB:
- > ADM515: MaxDB (SAP DB) Database Administration
NEW -> UMEW50: MaxDB Database Administration (Workshop)
- > WB550: Workshop MaxDB Internals
- > UMEW60: MaxDB/SAP DB Performance Monitoring & Optimization
You will receive detailed information about these courses by specifying the course name in the course search in the SAP training catalog in SapNet: www.sap.com/training
51. Are there any additional FAQ notes about MaxDB?
Yes, we are currently developing a number of FAQ notes about MaxDB. If you search for notes under the keyword 'FAQ' with the BC-DB-SDB component, all currently available FAQ notes are displayed.
52. Where do I find more information about MaxDB?
SAP employees can find additional information about MaxDB in BIS.
You can find documentation about MaxDB in the SAP Developer Network (SDN) at https://www.sdn.sap.com/irj/sdn/maxdb.
You can also search for notes that may contain additional information about MaxDB - all MaxDB notes are created at least as an additional component under BC-DB-SDB.