The following are the release notes for HammerDB v4.8.
From version 4.0 In the database.xml file and the User Interface the workload names have changed to TPROC-C and TPROC-H. This is a nomenclature change only to represent that the workloads are fair use implementations derived from the TPC specifications and the nomenclature does not change the functionality of the workload compared to prior versions using the TPC-C and TPC-H terminology.
From version 4.0 the stored procedures for the Oracle and PostgreSQL TPROC-C workloads have been refactored. From version 4.5 the stored procedures for the SQL Server TPROC-C have been refactored and MySQL, MariaDB and Db2 modified. This increases the expected performance between versions and consequently the performance from HammerDB v4.5 & HammerDB v4.0 cannot be compared directly to the performance of v3.3 or previous releases dependent on the database being tested. Additionally for some workloads HammerDB v45/v4.0 changed the relationship between the NOPM and TPM metrics compared to previous versions. As a result of the stored procedure refactoring using bulk operations more work is processed per commit and therefore in these cases the NOPM has increased whilst the TPM remains the same. This indicates a real measure of increased throughput by doing more work per database transaction and consequently NOPM is now listed first as the primary metric in reporting output. However as raised in HammerDB GitHub Issue #111 there may be cases where there is a dependency on the wording of the HammerDB log. For this reason a configuration option in the generic.xml file of first_result is given. If this option is set to NOPM then the v4.0 format is used if set to TPM then the output is compatible with v3.3.
<benchmark>
<rdbms>Oracle</rdbms>
<bm>TPC-C</bm>
<first_result>NOPM</first_result>
</benchmark>From v4.8 the HammerDB Web Service has been enhanced to provide a read only interface to the jobs output from both the GUI and CLI stored in a SQLite database using a web browser. This enables the viewing of workload configuration as well as automatically generated charts from the job output. These charts use Apache e-charts and therefore to access the charts it is necessary for the viewing browser to have an internet connection to download the the e-chart functionality. If the browser cannot access the e-charts URL the chart pages will remain blank. Chapter 10 provides further details on viewing Jobs with the Web Service.
HammerDB has a dependency on 3rd party driver libraries to connect to the target databases. The following are known issues with some of the 3rd party drivers that HammerDB uses.
If you are running HammerDB against Oracle on Windows there is long established bug in Oracle that can cause application crashes for multi-threaded applications on Windows.This bug can be investigated on the My Oracle Support website with the following reference. Bug 12733000 OCIStmtRelease crashes or hangs if called after freeing the service context handle. To resolve this Oracle issue add the following entry to the SQLNET.ORA file on your HammerDB client.
SQLNET.AUTHENTICATION_SERVICES = (NTS) DIAG_ADR_ENABLED=OFF DIAG_SIGHANDLER_ENABLED=FALSE DIAG_DDE_ENABLED=FALSE
Using the HammerDB client for SQL Server on Linux can be slower than the same client on Windows when using the default installed unixODBC drivers on many Linux distributions. As described in the SQL Server Programming Guidelines "When using the driver with highly multithreaded applications, unixODBC's handle validation may become a performance bottleneck. In such scenarios, significantly more performance may be obtained by compiling unixODBC with the --enable-fastvalidate option. However, beware that this may cause applications which pass invalid handles to ODBC APIs to crash instead of returning SQL_INVALID_HANDLE errors." Recompiling unixODBC with the --enable-fastvalidate option has been measured to improve client performance by 2X. Example configure options used to build unixODBC are shown as follows:
./configure --prefix=/usr/local/unixODBC --enable-gui=no --enable-drivers=no --enable-iconv
--with-iconv-char-enc=UTF8 --with-iconv-ucode-enc=UTF16LE --enable-threads=yes --enable-fastvalidateWhen running the HammerDB Docker image, drivers for all databases are pre-installed except for Db2. This is because the required redistributable IBM® Data Server Driver for ODBC and CLI is not available to be pulled automatically within the build and the IBM documentation lacks clarity on the conditions for whether a copy of the redistributable package can be made available by HammerDB "royalty-free". Therefore any user of Db2 must download and install their own Db2 client after installing Docker. This issue is tracked in Issue #404.
On Linux the HammerDB GUI requires the Xft FreeType-based font drawing library for X installed as follows:
Ubuntu:
$ sudo apt-get install libxft-dev
Red Hat:
$ yum install libXft
On Linux HammerDB GUI requires Cairo Graphics installed to support the graphical transaction counter and can be installed as follows:
Ubuntu:
sudo apt-get install libcairo2-dev
Red Hat:
ymu install cairo-devel