Re: [sqlite] Multiprocess accessing SQLite connection

On 6/17/2013 9:57 AM, Vijay Khurdiya wrote: > Do we can use attach & deattach option to read the other DB file data from > other process.? Yes you can, but you'd have exactly the same concurrency-related restrictions as when you open multiple connections to the same file directly. Connecting

Re: [sqlite] Feature request: add support for COMMENT statement

On Jun 17, 2013, at 6:14 PM, Roman Fleysher wrote: > Dear SQLiters, First thing first… don't hijack a thread… instead start a new one, with a new subject. > Can someone recommend an ORM? No. > What are the pros and cons of using them?

Re: [sqlite] Multiprocess accessing SQLite connection

On 6/17/2013 9:57 AM, Vijay Khurdiya wrote: Do we can use attach & deattach option to read the other DB file data from other process.? Yes you can, but you'd have exactly the same concurrency-related restrictions as when you open multiple connections to the same file directly. Connecting

Re: [sqlite] GROUP BY syntax

", and also the value of field2 that corresponds to the maximum field3" <<< now that is useful. Many thanks. Dave Ward Analytics Ltd - information in motion Tel: +44 (0) 118 9740191 Fax: +44 (0) 118 9740192 www: http://www.ward-analytics.com Registered office address: The Oriel, Sydenham Road,

Re: [sqlite] Feature request: add support for COMMENT statement

Dear SQLiters, I can not add solutions, since I am a physicist designing database for the first time, but I would like to add questions... Object-relational mapping (ORM) is a new and interesting concept for me that I learned. I will read about it more. However, I do not understand why new

Re: [sqlite] GROUP BY syntax

On Mon, Jun 17, 2013 at 12:03 PM, Dave Wellman wrote: > Hi, > > Igor and Richard - thanks for your answers. > > Following up on the example below from Igor, what is the use case ? > SELECT field1, field2, max(field3) FROM table GROUP BY field1; The above returns the

Re: [sqlite] GROUP BY syntax

Hi, Igor and Richard - thanks for your answers. Following up on the example below from Igor, what is the use case ? select field1, field2, sum(field3) group by field1; If the answer set contains one row per field1 value and an arbitrary value for field2 - what does this answer provide? -

Re: [sqlite] Multiprocess accessing SQLite connection

Yes... but it should be clear that each process will have only access to the data it has written and it won't have Access to the data written by other processes. > I am not sure writing from other process is possible, provided other process > opening the connection to that DB file. > Do we can

Re: [sqlite] Multiprocess accessing SQLite connection

Yes... but it should be clear that each process will have only access to the data it has written and it won't have access to the data written by other processes. On Mon, Jun 17, 2013 at 3:08 PM, Igor Tandetnik wrote: > On 6/17/2013 1:01 AM, Vijay Khurdiya wrote: >> >> In that

Re: [sqlite] Simple Group By slowing queries by 6x

create index ddate_hits_a_idadvertiser_site_hostname_bench on a_idadvertiser_site_hostname_bench (ddate, hits); --- () ascii ribbon campaign against html e-mail /\ www.asciiribbon.org > -Original Message- > From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users- >

Re: [sqlite] Multiprocess accessing SQLite connection

On 6/17/2013 1:01 AM, Vijay Khurdiya wrote: In that case can I have separate DB file associated with each process. Of course. Just pass different file names to sqlite3_open or similar. -- Igor Tandetnik ___ sqlite-users mailing list

Re: [sqlite] GROUP BY syntax

On 6/17/2013 8:36 AM, Dave Wellman wrote: So I think that what this is saying is that when you execute an aggregate query without a GROUP BY, the chosen non-aggregate values are random (i.e. arbitrary). This is true with GROUP BY as well - consider: select field1, field2, sum(field3) group by

Re: [sqlite] GROUP BY syntax

On Mon, Jun 17, 2013 at 8:36 AM, Dave Wellman wrote: > > > So I think that what this is saying is that when you execute an aggregate > query without a GROUP BY, the chosen non-aggregate values are random (i.e. > arbitrary). > > If there is exactly one aggregate

[sqlite] GROUP BY syntax

Hi, The following sql was in a recent post which was complaining about performance and it looks like a solution has been provided for that. However, looking at the original SQL I would have expected an error message to be generated for it because there is no "GROUP BY" clause. SELECT

Re: [sqlite] Simple Group By slowing queries by 6x

Iván de Prado wrote: > SELECT ddate, sum(hits) from a_idadvertiser_site_hostname_bench where ddate < > '2013-08-01' group by ddate; > > SCAN TABLE a_idadvertiser_site_hostname_bench (~33 rows) > USE TEMP B-TREE FOR GROUP BY > > [...] means that this query is running almost 6 times slower than

Re: [sqlite] Simple Group By slowing queries by 6x

Seems that using pragma temp_store=2 improves the speed. It now tooks 20 seconds. So now the penalty time is 9 seconds. It would possible to improve it?. Regards. Iván 2013/6/17 Iván de Prado > I have query where adding a simple "group by" by date is slowing the query > too

[sqlite] Simple Group By slowing queries by 6x

I have query where adding a simple "group by" by date is slowing the query too much, from my point of view. The following query: SELECT ddate, sum(hits) from a_idadvertiser_site_hostname_bench where ddate < '2013-08-01'; runs in 12 seconds. Approximately 423,327 rows scanned per second. 1 row

[sqlite] optimization for outer join with most simple views

Hello, Suppose one has an expression on the columns of a single table, say x +y, and that this expression occurs in multiple queries. Then it is attractive to define it at a single place, using a view: create view v as select *, x+y as a from t; I had hoped that substituting such a

Re: [sqlite] Pager bugs(?)

> statement is only doing pointer arithmetic Apparently it is so. But it is not obvious. This code would be cleaner and faster: ... if( pPage ){ pcache1PinPage(pPage); goto fetch_out; } if( createFlag==0 ){ return NULL; ... Have a good day. With best regards,

[sqlite] use sqlite to count macd value

DIFF : EMA(CLOSE,SHORT) - EMA(CLOSE,LONG); DEA  : EMA(DIFF,M); MACD : 2*(DIFF-DEA), COLORSTICK; I wanna use sqlite to count macd value, have any idea? thank you! ___ sqlite-users mailing list sqlite-users@sqlite.org

Re: [sqlite] Computed columns in VIEWs return NULL but should be able to be typed! Any ideas?

Thanks Stephan for your feedback. Bad news for me. I see two solutions: - hire a dev for this. I'm not following enough sqlite lists to estimate if this is feasible. Any opinion? - hire a QGIS dev to hack a autodetection of type using content of fields. Ugly, probably slow and prone to errors..