[Zope-dev] Re: [DB-SIG] SQLite as a Light DB component for Zope and Python

[Magnus Lyckå]

At 17:54 2002-04-01 -0800, William Trenker wrote:
>but a greenhorn at extending Python yet I had a
>crude but working Python extension module for
>SQLite up and running in 2 days

So, we expect to see the announcement of a DB-API 2
complient SQLite driver any day then! :-)

>Implements a large subset of SQL92.

I'd say a small subset, or perhaps sideset:

SQLite implements the follow syntax:
·   BEGIN TRANSACTION (END COMMIT ROLLBACK)
·   COPY
·   CREATE INDEX
·   CREATE TABLE
·   CREATE VIEW
·   DELETE
·   DROP INDEX
·   DROP TABLE
·   DROP VIEW
·   EXPLAIN
·   expression
·   INSERT
·   ON CONFLICT clause
·   PRAGMA
·   REPLACE
·   SELECT
·   UPDATE
·   VACUUM
(Or at least that's what the language reference at
http://www.hwaci.com/sw/sqlite/lang.html says.)

No GRANT / REVOKE or any other kind of security.
It seems to be a plain single user thingie.

No ALTER TABLE, SET TRANSACTION etc. Ok, these aren't
actually in Entry SQL 92, but everybody else has them...

And COPY, PRAGMA, REPLACE, VACUUM, ON CONFLICT etc is
not in any SQL standard I know of.

It violates SQL92 in a number of ways it seems. For
inststance, it's typeless (like GadFly) which means that
for instance "00" == "0". There are a lot of error
checking in SQL that this engine won't do.

SQLite ignores checks in CREATE TABLE and has no foreign
keys?

But it seems a bit closer to SQL than GadFly...and apart
from typelessness it seems to support rather extensive
SELECT statements. It might be a very useful thing I guess.
There are plenty of cases where installing an RDBMS is
overkill.

>Small memory footprint: less than 20K lines of C code.

Erh? Measuring memory footprint in kLoC seems a bit like
measuring mass in meters. Although according to the 2.4.0
release notes at freshmeat it seems the binary image needs
less than 200kB! Question is how much RAM that actual data
requires. If it lifts entire tables into RAM it might be
very memory hungry for large databases.

>Four times faster than PostgreSQL. Twice as fast as SQLite 1.0.

Yea yea, it just depends on what you measure. And how.
PostgreSQL is infinitely faster on the features SQLite
doesn't support... Benchmarking is a bit too complex to
just describe like a scalar like that.

>The author, D. Richard 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.

So, how active is the mailing list? And how good? I saw
a subscribe link, but no archive (maybe I just missed it.)



-- 
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[Zope-dev] Re: [DB-SIG] SQLite as a Light DB component for Zope and Python

[jose]

I'm working with SQLite right now, I find it a very interesting product, 
SQLite is tiny, fast,
I think it is fast at least as MySQL but SQLite has TRANSACTIONS and it 
easy to install,
for now it  needs a python interface based on DB-SIG.
IMO SQLite is a good candidate to replace Gadflay

 
Jo

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 SQLite: 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, D. Richard  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)
> torahteacher.com
> 
>
>
>
>
>
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[Zope-dev] Re: [DB-SIG] SQLite as a Light DB component for Zope and Python

[jose]

Magnus Lyckå wrote:

> At 17:54 2002-04-01 -0800, William Trenker wrote:
>
>> but a greenhorn at extending Python yet I had a
>> crude but working Python extension module for
>> SQLite up and running in 2 days
>
>
> So, we expect to see the announcement of a DB-API 2
> complient SQLite driver any day then! :-)
>
>> Implements a large subset of SQL92.
>
>
> I'd say a small subset, or perhaps sideset: 

If you campare it with OCELOT you are right but you have to compare it 
with Gadflay.

>
>
> SQLite implements the follow syntax:
> ·   BEGIN TRANSACTION (END COMMIT ROLLBACK)
> ·   COPY
> ·   CREATE INDEX
> ·   CREATE TABLE
> ·   CREATE VIEW
> ·   DELETE
> ·   DROP INDEX
> ·   DROP TABLE
> ·   DROP VIEW
> ·   EXPLAIN
> ·   expression
> ·   INSERT
> ·   ON CONFLICT clause
> ·   PRAGMA
> ·   REPLACE
> ·   SELECT
> ·   UPDATE
> ·   VACUUM
> (Or at least that's what the language reference at
> http://www.hwaci.com/sw/sqlite/lang.html says.)
>
> No GRANT / REVOKE or any other kind of security.
> It seems to be a plain single user thingie.
>
> No ALTER TABLE, SET TRANSACTION etc. Ok, these aren't
> actually in Entry SQL 92, but everybody else has them...
>
> And COPY, PRAGMA, REPLACE, VACUUM, ON CONFLICT etc is
> not in any SQL standard I know of.
>
> It violates SQL92 in a number of ways it seems. For
> inststance, it's typeless (like GadFly) which means that
> for instance "00" == "0". There are a lot of error
> checking in SQL that this engine won't do.
>
> SQLite ignores checks in CREATE TABLE and has no foreign
> keys?
>
> But it seems a bit closer to SQL than GadFly...and apart
> from typelessness it seems to support rather extensive
> SELECT statements. It might be a very useful thing I guess.
> There are plenty of cases where installing an RDBMS is
> overkill.
>
>> Small memory footprint: less than 20K lines of C code.
>
>
> Erh? Measuring memory footprint in kLoC seems a bit like
> measuring mass in meters. Although according to the 2.4.0
> release notes at freshmeat it seems the binary image needs
> less than 200kB! Question is how much RAM that actual data
> requires. If it lifts entire tables into RAM it might be
> very memory hungry for large databases.
>
>> Four times faster than PostgreSQL. Twice as fast as SQLite 1.0.
>
>
> Yea yea, it just depends on what you measure. And how.
> PostgreSQL is infinitely faster on the features SQLite
> doesn't support... Benchmarking is a bit too complex to
> just describe like a scalar like that.
>
>> The author, D. Richard 
>> 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.
>
>
> So, how active is the mailing list? And how good? I saw
> a subscribe link, but no archive (maybe I just missed it.)
>
>
The SQLite mailing list is very active. I am a list member.

Jos



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