Hi guys,
In an attempt to understand a slow query I've had a quick look at the
contents of the sqlite_stat1 table. It looks like the stat column contains
a series of integers like:
...
Is this observation correct? And if so, does sqlite essentially assume that
the rows are equally distributed
On Thu, Apr 28, 2016 at 5:53 PM, Richard Hipp wrote:
> > It looks like the ENABLE_STAT2/STAT4 options generate histogram data
> which
> > would probably help for non-uniform data?
>
> Yes, STAT4 provides histogram data to help with query planning on
> tables with non-uniform data distributions.
On Thu, Apr 28, 2016 at 5:28 PM, Rowan Worth wrote:
> In an attempt to understand a slow query I've had a quick look at the
> contents of the sqlite_stat1 table. It looks like the stat column contains
> a series of integers like:
>
>
>
>
> ...
>
> Is this observation correct? And if so, does s
On 4/28/16, Richard Hipp wrote:
> On 4/28/16, Dominique Devienne wrote:
>>
>> Richard, is STAT3 or STAT4 required for
>> https://www.sqlite.org/optoverview.html#skipscan ?
>> Or essential for skip-scan to bring the most benefit? --DD
>
> No. But sqlite_stat1 data is. Skip-scan is only attempted
On 4/28/16, Dominique Devienne wrote:
>
> Richard, is STAT3 or STAT4 required for
> https://www.sqlite.org/optoverview.html#skipscan ?
> Or essential for skip-scan to bring the most benefit? --DD
No. But sqlite_stat1 data is. Skip-scan is only attempted if there
are an average of 18 or more rep
On 4/28/16, Rowan Worth wrote:
> Hi guys,
>
> In an attempt to understand a slow query I've had a quick look at the
> contents of the sqlite_stat1 table. It looks like the stat column contains
> a series of integers like:
>
>
>
>
> ...
>
> Is this observation correct? And if so, does sqlite ess
On 2015-09-10 09:05 AM, Ludovic Aubert wrote:
> Hello,
>
> I am facing a strange issue:
> I am calling sqlite3_execute(db, "ANALYZE;") from a C program after a bunch
> of CREATE and INSERT,
> Then this program exits.
> Another exe tries to perform some selects into the db, but it seems like
> ANA
On 10 Sep 2015, at 8:05am, Ludovic Aubert wrote:
> I am calling sqlite3_execute(db, "ANALYZE;") from a C program after a bunch
> of CREATE and INSERT,
> Then this program exits.
Are you checking the result returned by that C call to make sure it is
SQLITE_OK ?
Simon.
Hello,
I am facing a strange issue:
I am calling sqlite3_execute(db, "ANALYZE;") from a C program after a bunch
of CREATE and INSERT,
Then this program exits.
Another exe tries to perform some selects into the db, but it seems like
ANALYZE had no effect and the queries take about 10 mn to complete
On Wed, Oct 16, 2013 at 10:29 AM, Daniel Polski wrote:
> Hello,
> Does the ANALYZE command gather statistics and optimize for views I've
> created or only "real tables"?
>
Only real tables.
Views are just macros that are applied to queries when the queries are run.
If you have:
CREATE TABL
Hello,
Does the ANALYZE command gather statistics and optimize for views I've
created or only "real tables"?
Best regards,
Daniel
___
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
On Mon, Jul 8, 2013 at 12:10 PM, Simon Slavin wrote:
> This question mostly applies to SQLite4, where a number of things will be
> changing anyway.
>
> How do folks feel about the ANALYZE command ? I started off thinking
> about wanting an 'ANALYZE OFF' command to delete the tables that ANALYZE
This question mostly applies to SQLite4, where a number of things will be
changing anyway.
How do folks feel about the ANALYZE command ? I started off thinking about
wanting an 'ANALYZE OFF' command to delete the tables that ANALYZE makes up.
But that just made me think that the ANALYZE comma
On 18 Aug 2011, at 2:03pm, Kristoffer Danielsson wrote:
> Hi, The problem is that the database is around 100 MB large (the error goes
> away if I remove unimportant data). Also, it contains data I'd like to keep
> private. I do have a specific select query that produces what I believe is a
> d
On Thu, Aug 18, 2011 at 9:03 AM, Kristoffer Danielsson <
kristoffer.daniels...@live.se> wrote:
>
> Hi, The problem is that the database is around 100 MB large (the error goes
> away if I remove unimportant data). Also, it contains data I'd like to keep
> private. I do have a specific select query
qlite.org
> Subject: Re: [sqlite] ANALYZE necessary after database upgrade?
>
> On Thu, Aug 18, 2011 at 8:50 AM, Kristoffer Danielsson <
> kristoffer.daniels...@live.se> wrote:
>
> >
> >
> >
> >
> > I have noticed that certain (complex) select quer
p the database and
send it to the sqlite team for analysis? > From: slav...@bigfraud.org
> Date: Thu, 18 Aug 2011 13:57:31 +0100
> To: sqlite-users@sqlite.org
> Subject: Re: [sqlite] ANALYZE necessary after database upgrade?
>
>
> On 18 Aug 2011, at 1:50pm, Kristoffer Danie
On Thu, Aug 18, 2011 at 8:50 AM, Kristoffer Danielsson <
kristoffer.daniels...@live.se> wrote:
>
>
>
>
> I have noticed that certain (complex) select queries return unexpected data
> (missing rows) on my upgraded SQLite databases.My guess is that the
> optimizer makes an erroneous decision on some
On 18 Aug 2011, at 1:50pm, Kristoffer Danielsson wrote:
> I have noticed that certain (complex) select queries return unexpected data
> (missing rows) on my upgraded SQLite databases.
What do you mean by 'upgraded' ?
> My guess is that the optimizer makes an erroneous decision on some index (I
I have noticed that certain (complex) select queries return unexpected data
(missing rows) on my upgraded SQLite databases.My guess is that the optimizer
makes an erroneous decision on some index (I'm using both sqlite_stat1 and
sqlite_stat2). Is this a reasonable guess? Is it necessary to r
The problem
---
I'm using the "ANALYZE" command of SQLITE to try and improve
performance for queries.
However, I'm finding that the actual analyze call can take a long time
to run for large amounts of rows (e.g. >2). This is especially the
case if a lot of data has been changed betwe
Thanks; I obviously missed something very essential there.
RBS
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: 30 December 2006 14:56
To: sqlite-users@sqlite.org
Subject: Re: [sqlite] Analyze before or after setting indices?
"RB Smissaert" <[EM
"RB Smissaert" <[EMAIL PROTECTED]> wrote:
> Doing some performance tweaking and wondering if there are any logical
> reasons why it would be better to analyze a table before or after setting
> the indices. I could figure it out by timing, but maybe somebody could tell
> me already why one is better
Doing some performance tweaking and wondering if there are any logical
reasons why it would be better to analyze a table before or after setting
the indices. I could figure it out by timing, but maybe somebody could tell
me already why one is better than the other.
RBS
-
Hi,
I recently downloaded sqlite source code via cvs repository.
In this source, I found out a new command
which name is "ANALYZE". (analyze.c)
It's like the oracle ANALYZE command, right ?
Please tell me more about it and how to use.
Sencerely,
Mikio Kishi
25 matches
Mail list logo
