2010-12-21
2010-12-21. Open Source › Synopse BigTable
Synopse Big Table is an open source Delphi unit for very fast data
storage and access, using key/values pairs.
If you just need to save raw data on disk, and retrieve it with an unique ID
number or string, this unit could fit your needs.
The unit has been deeply rewritten for the new version 1.12.
Main enhancements are great speed improving, less disk space use, new dedicated methods (and direct update of any record content).
2010-12-18
2010-12-18. Open Source › mORMot Framework
Up to now, most SQL statements were parsed, then prepared before
execution.
Only individual TSQLRecord content retrieval was using prepared statements.
For the upcoming version 1.12 of the framework, we added an internal SQL
statement cache in the database access.
That is, if a previous SQL statement is run with some parameters, a prepared
version, available in cache, is used, and new parameters are bounded to it
before the execution by SQLite3.
In some cases, it can speed the SQLite3 process a lot.
2010-12-17
2010-12-17. Pascal Programming
In a message posted in the EMB forum, Anthony wrote that he "inherited this stuff"... Maintaining a Delphi application pays the bills, but... is sometimes frustrating.
Here are some advices or experiment sharing.
2010-12-13
2010-12-13. Open Source › mORMot Framework
The Synopse SQLite3 Database Framework was just released under version 1.11:
- internal SQLite3 database engine is updated to version 3.7.4;
- new TSQLRecordMany to handle "has many" and "has many through"
relationships;
- new TSQLRecordFTS4 class, to handle the new FTS4 extension module;
- new RANK() function available in SQL statements for ranking FTS3/FTS4;
- introduces new TSQLite3DB, TSQLite3Statement, TSQLite3Blob, TSQLite3Value and
TSQLite3FunctionContext types to clarify SQLite3 internal handle usage;
- new sqlite3_busy_timeout and sqlite3_busy_handler low-level functions, with
new TSQLDataBase.BusyTimeout property;
- now handles User Defined Functions, via sqlite3_create_function_v2 and
corresponding sqlite3_result_* functions;
- new MOD() and SOUNDEX() functions available in SQL statements;
- a lot of code refactoring, speed improvements, numerous fixes, new
methods.
2010-12-04
2010-12-04. Open Source › Open Source libraries
We just released a new unit to the source code repository.
It's a simple, small and compact MM, built on top of the main Memory Manager(FastMM4 is a good candidate, standard since Delphi 2007), architectured in order to scale on multi core CPU's (which is what FastMM4 is lacking).
Original code is ScaleMM - Fast scaling memory manager for Delphi by André Mussche.
2010-12-04. Pascal Programming
It was told on this Blog that the Delphi memory manager (FastMM4 since Borland 2006 - but it was even worse with the previous "Borland's" MM), doesn't scale well on multi-code CPU. That is, if you have a multi-threaded application with a lot of memory handling (e.g. aString := aString+someString), the Delphi MM won't scale with multi cores. When I mean "don't scale", I mean that the optimistic though of "my CPU has 4 cores, therefore the same work run in 4 threads will be 4 times faster than with 1 thread" is false. It performs even worse with multiple threads than with 1 thread...
So we went into forking a nice project, named ScaleMM, and created our scalable optimized MM, named SynScaleMM. Our forked modifications were even included in the main ScaleMM branch.
During my profiling of our SynScaleMM, I discovered some very nice results with Delphi compiler inlining features.
