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| <title>23. IBM solidDB</title><link rel="stylesheet" href="css/docbook.css" type="text/css"><base href="display"><meta name="generator" content="DocBook XSL Stylesheets V1.72.0"><link rel="start" href="manual.html" title="Apache OpenJPA 2.1 User's Guide"><link rel="up" href="supported_databases.html" title="Appendix 2. Supported Databases"><link rel="prev" href="dbsupport_postgresql.html" title="22. PostgreSQL"><link rel="next" href="dbsupport_sybase.html" title="24. Sybase Adaptive Server"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">23. |
| IBM solidDB |
| </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="dbsupport_postgresql.html">Prev</a> </td><th width="60%" align="center">Appendix 2. |
| Supported Databases |
| </th><td width="20%" align="right"> <a accesskey="n" href="dbsupport_sybase.html">Next</a></td></tr></table><hr></div><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="dbsupport_soliddb"></a>23. |
| IBM solidDB |
| </h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="dbsupport_soliddb.html#dbsupport_soliddb_table_types">23.1. |
| M-type tables vs. D-type tables |
| </a></span></dt><dt><span class="section"><a href="dbsupport_soliddb.html#dbsupport_soliddb_concurrency_control">23.2. |
| Concurrency control mechanism |
| </a></span></dt></dl></div><div class="example"><a name="example_props_soliddb"></a><p class="title"><b>Example 2.23. |
| Example properties for IBM solidDB |
| </b></p><div class="example-contents"><pre class="programlisting"> |
| openjpa.ConnectionDriverName: solid.jdbc.SolidDriver |
| openjpa.ConnectionURL: jdbc:solid://localhost:2315/dba/dba |
| </pre></div></div><br class="example-break"><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="dbsupport_soliddb_table_types"></a>23.1. |
| M-type tables vs. D-type tables |
| </h3></div></div></div><p> |
| IBM solidDB supports two types of tables: in-memory tables (M-tables) and |
| on-disk tables (D-tables). Since cursor hold over commit can not apply to M-tables |
| (which will cause SOLID Table Error 13187: The cursor cannot continue |
| accessing M-tables after the transaction has committed or aborted. |
| The statement must be re-executed), the default OpenJPA tables are D-tables. |
| One can set the whole server to disk-based mode by adding |
| [General] |
| DefaultStoreIsMemory=no |
| in solid.ini. The table types can also be determined by setting OpenJPA property |
| "openjpa.jdbc.DBDictionary" with value "storeIsMemory=true" or "storeIsMemory=false" |
| in the persistence.xml. The "STORE MEMORY" and "STORE DISK" will be appended to |
| the create table DDL, respectively. |
| </p></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="dbsupport_soliddb_concurrency_control"></a>23.2. |
| Concurrency control mechanism |
| </h3></div></div></div><p> |
| The default concurrency control mechanism depends on the table type: |
| Disk-based tables (D-tables) are by default optimistic. |
| Main-memory tables (M-tables) are always pessimistic. |
| Since OpenJPA applications expects lock waits as usually is done with |
| normal pessimistic databases, the server should be set to the pessimistic mode. |
| The optimistic mode is about not waiting for the locks at all. That increases |
| concurrency but requires more programming. The pessimistic mode with the |
| READ COMMITTED isolation level (default) should get as much concurrency as one |
| might need. The pessimistic locking mode can be set in solid.ini: |
| [General] |
| Pessimistic=yes |
| One can override the locking mode on the per table base by setting OpenJPA property |
| "openjpa.jdbc.DBDictionary" to value "lockingMode=PESSIMISTIC" in the persistence.xml. |
| An extra SQL will be generated along with CREATE TABLE DDL: |
| ALTER TABLE EX_POBJECT SET PESSIMISTIC. |
| The possible values for lockingMode is OPTIMISTIC/PESSIMISTIC. |
| </p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="dbsupport_postgresql.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="supported_databases.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="dbsupport_sybase.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">22. |
| PostgreSQL |
| </td><td width="20%" align="center"><a accesskey="h" href="manual.html">Home</a></td><td width="40%" align="right" valign="top"> 24. |
| Sybase Adaptive Server |
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