Re: [Zope-dev] SQLite as a Light DB component for Zope and Python
Very interesting. I think I've read about this somewhere before. The claim of 4x faster than PostgreSQL raised my brow. It is true that Gadfly is becoming quite stale, and only supports a *very* limited subset of SQL. It also would be nice to see something a bit more robust than just shelve in the Standard Library. Gadfly is ok to begin a prototype in, but frustrating once you quickly hit a glass ceiling in functionality. I'm interested in seeing how well it can scale, versus Postgres, however. Any experience? Thanks for the info, Eron Lloyd On Mon, 2002-04-01 at 20:54, William Trenker wrote: I have noticed on the DB lists lately some concern about the future of Gadfly. I have been investigating a marvelous little open-source, no copyright, SQL engine called http://www.hwaci.com/sw/sqlite/index.htmlSQLite: An SQL Database Engine In A C Library. I am quite experienced with Python, reasonably experienced with Zope but a greenhorn at extending Python yet I had a crude but working Python extension module for SQLite up and running in 2 days (most of that time figuring out the Python extension conventions). I think Python needs a lightweight SQL engine as a standard module, and I think this would be a good Zope product candidate as well. I'm proposing SQLite as that engine. Here is the developer's feature list, taken from the link given above: Implements a large subset of SQL92. A complete database (with multiple tables and indices) is stored in a single disk file. Atomic commit and rollback protect data integrity. Small memory footprint: less than 20K lines of C code. Four times faster than PostgreSQL. Twice as fast as SQLite 1.0. Very simple C/C++ interface requires the use of only three functions and one opaque structure. TCL bindings included. A TCL-based test suite provides near 100% code coverage. Self-contained: no external dependencies. Built and tested under Linux and Win2K. Sources are uncopyrighted. Use for any purpose. The SQLite source code is 35% comment. These comments are another important source of information. The author, mailto:[EMAIL PROTECTED]D. Richard mailto:[EMAIL PROTECTED]Hipp, is a computer science Ph.D. who knows his stuff. This is not green software, it is well designed and tested. It was first released in May 2000 and is very actively updated and supported. Thanks for listening. Bill Trenker Internet Applications Developer Kelowna, BC, Canada The commandments of the LORD are right, bringing joy to the heart. The commands of the LORD are clear, giving insight to life . . . For this is the love of God, that we keep His commandments. And His commandments are not burdensome. (Psalm 19:8, 1John 5:3)http://torahteacher.com/torahteacher.com --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.343 / Virus Database: 190 - Release Date: 3/22/02 --- [This E-mail scanned for viruses by Declude Virus] ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] SQLite as a Light DB component for Zope and Python
On Tue, Apr 02, 2002 at 10:02:22AM -0500, Eron Lloyd wrote: Very interesting. I think I've read about this somewhere before. The claim of 4x faster than PostgreSQL raised my brow. It is true that Gadfly is becoming quite stale, and only supports a *very* limited subset of SQL. It also would be nice to see something a bit more robust than just shelve in the Standard Library. Gadfly is ok to begin a prototype in, but frustrating once you quickly hit a glass ceiling in functionality. I'm interested in seeing how well it can scale, versus Postgres, however. Any experience? Scale, as in multiuser? Hardly at all: it's an SQL library that accesses a single, textbased, flatfile for the entire database. From the FAQ, multiple readers are allowed (on Unix), but the entire file (yes, that's the whole database, not a single table) is locked for one backend to write. As a lightweight replacement for gadfly, it looks like it might be pretty good. Note that the scripting language of choice of the author seems to be Tcl, rather than Python. This probably explains the 'everything is a string' approach :-) The speed comparisions with PostgreSQL are very much an apples vs. fish sort of thing: the pgsql server was not tuned _at all_, and does a whole lot more that was never tested, such as multi-user writer access. Ross ___ Zope-Dev maillist - [EMAIL PROTECTED] http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] SQLite as a Light DB component for Zope and Python
At 10:45 AM 4/2/02 -0600, Ross J. Reedstrom [EMAIL PROTECTED] wrote: Scale, as in multiuser? Hardly at all: it's an SQL library that accesses a single, textbased, flatfile for the entire database. As a lightweight replacement for gadfly, it looks like it might be pretty good. Exactly. I'm proposing this as a lightweight component, just as you say, not as a replacement for something like MySQL or PostgreSQL. What I have in mind is a small, simple, built-in SQL engine that could be used as a step up from something like TinyTablePlus in Zope and be compact enough to even be considered as a module candidate for the standard Python library. Note that the scripting language of choice of the author seems to be Tcl, rather than Python. This probably explains the 'everything is a string' approach :-) If you look into the C interface you will find it is almost trivial to build a Python extension module and bring SQLite into the realm of Python scripting. SQLite also has it's own C interface for adding expression functions and aggregates to the SQL syntax. I expect this could be hooked into Python through the Python extension interface as a callback. Again, the everything is a string approach fits in with the idea of simple, lightweight. Mind you, SQLite supports SQL expressions so it can do things like SELECT * FROM my_table WHERE my_field / 2 23.8, or INSERT INTO my_table VALUES (100 / 30.0). SQLite does implicit conversions, as required. The speed comparisions with PostgreSQL are very much an apples vs. fish sort of thing: the pgsql server was not tuned _at all_, and does a whole lot more that was never tested, such as multi-user writer access. You could be right. I'm not an expert with PostgreSQL so I can't comment. But, at the risk of being repetitious, I'm thinking lightweight. My intent is to propose a small relational tool that doesn't impose a significant overhead on the host system and might be simple enough that the Zope and Python developers would consider SQLite, together with a Python DB API and Zope DA, for their standard libraries. Thanks for commenting, Bill The commandments of the LORD are right, bringing joy to the heart. The commands of the LORD are clear, giving insight to life . . . For this is the love of God, that we keep His commandments. And His commandments are not burdensome. (Psalm 19:8, 1John 5:3)http://torahteacher.com/torahteacher.com --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.343 / Virus Database: 190 - Release Date: 3/22/02
