Re: [sqlite] Not reading data in the -wal file? (Not Reproducible)

Thank you to Igor and Richard. I've studied this issue more, and still don't have an answer, although I've not been able to reproduce it either. I'm not using shared cache, and even if I did leave a database connection open, which seems impossible since sqlite3_open(), sqlite3_finalize() and

Re: [sqlite] Query on primary key not using primary key?

Without additional information, SQLite guesses that the data_idx index will narrow down the search to about 7 entries in the table. This is, of course, a guess, but it is a reasonable guess for most indices. The primary key, even though it is unique, has an IN clause with 50 entries, it SQLite

Re: [sqlite] Query on primary key not using primary key?

On Fri, Jun 7, 2013 at 12:56 PM, Brad House wrote: > I would expect all queries which specify the primary key components >>> in the WHERE clause to use the Primary Key in the query plan, regardless >>> of if ANALYZE has been run or not. >>> >>> >> SQLite examines many

Re: [sqlite] An "unable to open database file" error that has nothing to do with opening database file

On 6/6/2013 21:56, Philip Goetz wrote: I think the problem is that the Cygwin distribution has the wrong version of SQLite, one built for unix. Nope. And even if true, it wouldn't be the right explanation. There are two major ways to build SQLite on Cygwin: 1. By default, building SQLite

Re: [sqlite] Query on primary key not using primary key?

On 06/07/2013 12:46 PM, Simon Slavin wrote: On 7 Jun 2013, at 5:37pm, Brad House wrote: I've modified my code to run an Analyze on startup to work around this, but it obviously takes time to run and slows down startup. I can't answer your question about why this happens

Re: [sqlite] Query on primary key not using primary key?

I would expect all queries which specify the primary key components in the WHERE clause to use the Primary Key in the query plan, regardless of if ANALYZE has been run or not. SQLite examines many different strategies for evaluating each query. For each strategy it tries to estimate the total

Re: [sqlite] Query on primary key not using primary key?

On 7 Jun 2013, at 5:37pm, Brad House wrote: > I've modified my code to run an Analyze on startup to work around this, > but it obviously takes time to run and slows down startup. I can't answer your question about why this happens in the first place, but I can tell you that

Re: [sqlite] Query on primary key not using primary key?

On Fri, Jun 7, 2013 at 12:37 PM, Brad House wrote: > I would expect all queries which specify the primary key components > in the WHERE clause to use the Primary Key in the query plan, regardless > of if ANALYZE has been run or not. > SQLite examines many different strategies

[sqlite] Query on primary key not using primary key?

I would expect all queries which specify the primary key components in the WHERE clause to use the Primary Key in the query plan, regardless of if ANALYZE has been run or not. I would also think it would assume any index which covers the most where-clause components would be the most efficient

Re: [sqlite] select count(*) does not use primary key??

On Fri, Jun 7, 2013 at 11:51 AM, Ryan Johnson wrote: > On 06/06/2013 10:52 AM, Gabriel Corneanu wrote: > >> In my opinion, count(*) is the same as count(rowid) (I see that even >> count() is accepted); I could say it's even the same as count(x) (any >> other >>

Re: [sqlite] select count(*) does not use primary key??

On 06/06/2013 10:52 AM, Gabriel Corneanu wrote: In my opinion, count(*) is the same as count(rowid) (I see that even count() is accepted); I could say it's even the same as count(x) (any other field). Not quite... count(x) only counts rows having non-NULL x. Granted, that's not a problem for

Re: [sqlite] MMIO and VFS Obfuscation

Quoth Drake Wilson , on 2013-06-07 08:18:05 -0500: > Actually, I dropped a paragraph on the floor, sorry. It's probably better to > use > xRead for this, since in that case SQLite will manage its own memory for the > cache > of decrypted pages. The loss in that case, if

Re: [sqlite] regexp.c

- Original Message - From: Richard Hipp To: phi...@blastbay.com ; General Discussion of SQLite Database Sent: Friday, June 07, 2013 1:14 PM Subject: Re: [sqlite] regexp.c On Fri, Jun 7, 2013 at 5:30 AM, Philip Bennefall wrote: Hello all,

Re: [sqlite] MMIO and VFS Obfuscation

Quoth Drake Wilson , on 2013-06-07 08:14:27 -0500: > If you really want, you might be able to implement xFetch to allocate a shadow > buffer, decrypt from the map into that, and return that pointer. Since it's > designed for accessing maps directly, though, I don't see it

Re: [sqlite] MMIO and VFS Obfuscation

Quoth Paul Vercellotti , on 2013-06-07 01:07:35 -0700: > The current system does in-place decryption on read (no copying), which adds > almost no overhead to the operation.    Now in-place decryption with a > memory-mapped file seems like it would dirty the page, which could >

Re: [sqlite] problem sqlite3 c++ please

On 6 Jun 2013, at 2:30pm, Maxime Gerum wrote: > but in c++, if i make request[4]= ”.mode csv” Commands starting with "." are specially built into the SQLite shell tool application. They are not part of SQLite itself and cannot be used just by using API calls. Sorry.

Re: [sqlite] FW: problem sqlite3 c++ please

Is this a repeated post? You cannot use shell commands as Sql statements in c api. Write your own export routine. Here is one I wrote. https://github.com/fnoyanisi/sqlite3_capi_extensions On 06/06/2013, at 11:02 PM, Maxime Gerum wrote: > > Hello, i’m french, sorry if

[sqlite] FW: problem sqlite3 c++ please

Hello, i’m french, sorry if i make errors of langage In my school project, i use sqlite3 with c++, i can make any request such as create table or select *from, no problems. But i would export my database in a csv file, in sqlite3> .mode csv

[sqlite] FW: problem sqlite3 c++ please

Hello, i’m french, sorry if i make errors of langage In my school project, i use sqlite3 with c++, i can make any request such as create table or select *from, no problems. But i would export my database in a csv file, in sqlite3> .mode csv

Re: [sqlite] select count(*) does not use primary key??

On Fri, 07 Jun 2013 13:12:14 +0200 Clemens Ladisch wrote: > Eduardo Morras wrote: > > where t.a = NULL > > where t.a IS NULL > > (NULL compares as not equal to any value, including itself.) OPppss you're right. Thought too fast and wrote even faster :( > > Regards, >

Re: [sqlite] regexp.c

On Fri, Jun 7, 2013 at 5:30 AM, Philip Bennefall wrote: > Hello all, > > I was having a quick look at the extensions provided in ext/misc in the > source tree, and I am pleasantly surprised at the number of useful things > that I found in there that I didn't know about. I was

Re: [sqlite] select count(*) does not use primary key??

Eduardo Morras wrote: > where t.a = NULL where t.a IS NULL (NULL compares as not equal to any value, including itself.) Regards, Clemens ___ sqlite-users mailing list sqlite-users@sqlite.org

Re: [sqlite] select count(*) does not use primary key??

On Thu, 6 Jun 2013 10:53:55 -0400 Richard Hipp wrote: > On Thu, Jun 6, 2013 at 10:52 AM, Gabriel Corneanu > wrote: > > > Strange is, count(*) uses the cover index for a but "select count(a)" does > > NOT use the same cover index... > > > > count(a)

Re: [sqlite] select count(*) does not use primary key??

This is not at all my case ... I don't obviously write 1 by 1, but using blocks of data ( array of struct ), virtual tables wrappers, and "insert ... select". This way I can achieve >200k rec/s, or at least 100k when having some more fields. Right now I'm completely CPU bound, it's 100% load

Re: [sqlite] Header Application-ID list

On Thu, 6 Jun 2013 08:15:57 -0400 Richard Hipp wrote: > On Thu, Jun 6, 2013 at 8:05 AM, Eduardo Morras wrote: > > > > > Hi, > > > > Is there an official list of assigned application id sqlite header? If > > exist, How can I register my application-id? > > >

[sqlite] regexp.c

Hello all, I was having a quick look at the extensions provided in ext/misc in the source tree, and I am pleasantly surprised at the number of useful things that I found in there that I didn't know about. I was wondering about the regular expression parser in particular. Does it support

Re: [sqlite] select count(*) does not use primary key??

On 7 Jun 2013, at 8:57am, Gabriel Corneanu wrote: > BTW I found this by opening some file over network, which of course made > everything worse. > [...] > Not that I really need, but I have to support specified data rates up to 100k > records / second. Maximum

[sqlite] MMIO and VFS Obfuscation

Hi there, We use a vfs-based obfuscation system using the old xRead and xWrite methods.   I'm wondering if these can be adapted to work with the new memory-mapped i/o functionality in a way that still has the advantages of memory-mapped i/o? The current system does in-place decryption on read

Re: [sqlite] select count(*) does not use primary key??

I admit I didn't think (or didn't even read in detail) about technical implementation. This is an extract from analyzer: *** Table AE_DATA Percentage of total database.. 99.89% Number of entries. 1030371 Bytes of