Re: [firebird-support] Re: tempdirectories
wobble...@yahoo.co.uk, > is there a good and up to date official source of documentation on > firebird.conf The firebird.conf file itself, version current for the Fb version you are using. You won't get more up to date than that anywhere. For Fb3, which allows per-database config for a lot of parameters, see the release notes. Some things are (or can be) configured at the client side via a config file now, too. > and other admin? What's "other admin"? The command-line tools are all documented but some could do with updating, admittedly. You can catch up with any new switches in those apps by running them with the -? switch. Vol. 3 of TFB2e covers them all in more detail, up to the earlier releases of Fb 2.5, but it's not free. HB --- This email has been checked for viruses by AVG. https://www.avg.com
Re: [firebird-support] Re: tempdirectories
30.07.2018 12:01, wobble...@yahoo.co.uk [firebird-support] wrote: > is there a good and up to date official source of documentation on > firebird.conf and other > admin? Description of firebird.conf is inside of it. -- WBR, SD. ++ Visit http://www.firebirdsql.org and click the Documentation item on the main (top) menu. Try FAQ and other links from the left-side menu there. Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ ++ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/
[firebird-support] Re: tempdirectories
is there a good and up to date official source of documentation on firebird.conf and other admin? I can't find anything in the https://www.firebirdsql.org/en/reference-manuals/ https://www.firebirdsql.org/en/reference-manuals/ that is as good as the older release notes, nor the janus software document. This https://www.firebirdsql.org/pdfmanual/html/qsg25-config.html https://www.firebirdsql.org/pdfmanual/html/qsg25-config.html list some configuration details, but I can see it hasn't got all of firebird.conf's options. (by "I can't find" I obviously mean that google can't find!)
Re: [firebird-support] Re: tempdirectories
Ian wrote: > We got the idea from The Firebird Book, and after that I can't find > mention of it being deprecated in 2.0 release notes or later. Not deprecated but abolished. If something is "deprecated", it is still valid but likely to be dropped in a subsequent release. From Fb 2 onward, Fb was made more tolerant of directory names with spaces, hence the need to drop such embellishments. (Not that made anything like sufficientt impact on my consciousness in 2013-4 to remember it affected TempDirectories - q.v.) > From > the 2004 book, page 745 (I know it's older than my daughter ;-): > "TempDirectories > Version 1.5 forward > Supply a list of one or more directories, separated by semicolons > (;), under which sort files may be stored. Each item may include an > optional size argument. in bytes, to limit its storage. > TempDirectories = userdata\sortfiles 500 > " It has subsequently become a myth that has survived into TFB Second Edition. I can fix that. > And also in the 1.5.6 release notes > https://firebirdsql.org/rlsnotesh/config-fb-conf.html, and then > hanging around in something that claims to be the Firebird 2 > Administrators manual, but now I look closer it isn't obvi ously a > core fb site: > http://www.janus-software.com/fbmanual/manual.php?book=admin=42 No, it's not. > I can't find it mentioned anywhere else though, except in things > like http://tracker.firebirdsql.org/browse/CORE-2151 where the author was > still using it... The author of that ticket was the developer who wrote the parser code. ;-) It looks as though he'd discovered unintended behaviour when the parser landed on a space in a directory name...the older code to truncate out anything following a space (i.e., assumed to be the now-invalid allocation size) was gaily truncating forward from the first space in the directory name itself. (That was an amazing piece of searching that dug that up!) Helen --- This email has been checked for viruses by AVG. https://www.avg.com
Re: [firebird-support] Re: tempdirectories
> 27.07.2018 21:41, Helen Borrie hele...@iinet.net.au [firebird-support] wrote: >> I don't know where you got the idea that you could specify the size of >> a temp directory. Dmitry replied >It is an Interbase feature. Uh...ok... @_@ If you want to allocate specific spaces for your temp directories on the hard disks, just create a couple of partitions of the sizes you had in mind. Helen --- This email has been checked for viruses by AVG. https://www.avg.com
Re: [firebird-support] Re: tempdirectories
27.07.2018 21:41, Helen Borrie hele...@iinet.net.au [firebird-support] wrote: > I don't know where you got the idea that you could specify the size of > a temp directory. It is an Interbase feature. -- WBR, SD. ++ Visit http://www.firebirdsql.org and click the Documentation item on the main (top) menu. Try FAQ and other links from the left-side menu there. Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ ++ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/
Re: [firebird-support] Re: tempdirectories
wobble...@yahoo.co.uk wrote: > I've just tried > TempDirectories = /location1 5000 ;/location2 ; /location3 > And location1 is ignored, but 2 and 3 used! Which tells you something. ;-) The engine doesn't recognise the format of the first member of the list but it's OK with the second and third because they are legal. I don't know where you got the idea that you could specify the size of a temp directory. It's never been a thing and it wouldn't make sense if it were. The idea of being able to specify multiple locations is that you can avoid an out-of-space crash if the engine has somewehere else to go when it needs to put temp files to disk and the first (or default) temp space is used up. Another point is that, if your user environment has a lot of users doing lots of ordered queries and keeping them alive for long periods, you can consider having a dedicated disk, such as a fast SSD, for TempDirectories. The engine holds the temp file structures in RAM if it can: it only puts them to disk if available RAM is too low. Hence, allocating a RAM disk for TempDirectories doesn't make sense, either. Helen --- This email has been checked for viruses by AVG. https://www.avg.com
[firebird-support] Re: tempdirectories
I've just tried TempDirectories = /location1 5000 ;/location2 ; /location3 And location1 is ignored, but 2 and 3 used!
Re: [firebird-support] Re: TempDirectories and ALTER INDEX ACTIVE
On 8-6-2012 18:07, Ann Harrison wrote: On Fri, Jun 8, 2012 at 11:24 AM, Alec Swan alecs...@gmail.com wrote: Thanks Vlad, but this is too complicated to give as a guidance to our customers. However, it sounds like rebuilding an index cannot require more space that the database size itself, right? On a bad day, yes it could. To have a day that bad, you'd have to have keys that are most of the size of the record, with columns that are often null, zero, or contain values much smaller than the declared size of the column. There may be a situation during the merge phase of the sort when there's more than one copy of each record. Question out of curiosity: why does an index rebuild actually require a sort? I would think that for an index rebuild this would be sufficient: * deactivate index * clear index * for each record (sequential read of all pages?) *insert column value into index * activate index These steps would not require any additional temporary space. -- Mark Rotteveel
Re: [firebird-support] Re: TempDirectories and ALTER INDEX ACTIVE
On 10-6-2012 12:32, Dmitry Yemanov wrote: 10.06.2012 14:09, Mark Rotteveel wrote: * for each record (sequential read of all pages?) * insert column value into index Inserting unsorted / random values into the b-tree is known to be much slower than sorting the values in advance and loading them into the b-tree in order. If the trade off is requiring a large part of memory or disk space extra (and the additional time required to perform the sort), then I do wonder if the advantage is really that big. The build of a balanced b-tree(*) is O(n log n), and the 'good' case of sorting is O(n log n) to O(n^2) (ideal is O(n)). Sorting before insertion might only be worth the effort if the sort can fully occur in memory. The additional overhead of writing to disk during the sort and reading from disk for insertion might negate most of the advantages against the overhead of inserting into the b-tree unsorted (ie balancing etc). It might be worth to investigate this tradeoff, or just to provide an option to rebuild indices without using temporary sort spaces so others can measure it for themselves (or to have a workaround if disk space is not large enough to accommodate the rebuild). *) I am assuming FB uses a balanced trees, because sorting first would otherwise degenerate it into a linked list -- Mark Rotteveel
Re: [firebird-support] Re: TempDirectories and ALTER INDEX ACTIVE
Thanks Vlad, but this is too complicated to give as a guidance to our customers. However, it sounds like rebuilding an index cannot require more space that the database size itself, right? On Fri, Jun 8, 2012 at 7:22 AM, hvlad hv...@users.sourceforge.net wrote: ** --- In firebird-support@yahoogroups.com, Alec Swan wrote: My main question is how can we calculate the temp sort space required to ALTER INDEX ACTIVE (on all indexes serially) given the size of the database? Is twice the size of the database a good upper bound? Enumerate all fields in index, calculate summa of full size of every field (for [var]char(N) it is N * bytes_per_char, for ex.), add extra 8 bytes (for record number) - this is sort record size. Multiply it by number of records and you'll get a lower estimate of temp space required. Substract value of TempCacheLimit and you'll get estimate of disk space required. Regards, Vlad [Non-text portions of this message have been removed] ++ Visit http://www.firebirdsql.org and click the Resources item on the main (top) menu. Try Knowledgebase and FAQ links ! Also search the knowledgebases at http://www.ibphoenix.com ++ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) * To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [firebird-support] Re: TempDirectories and ALTER INDEX ACTIVE
On Fri, Jun 8, 2012 at 11:24 AM, Alec Swan alecs...@gmail.com wrote: Thanks Vlad, but this is too complicated to give as a guidance to our customers. However, it sounds like rebuilding an index cannot require more space that the database size itself, right? On a bad day, yes it could. To have a day that bad, you'd have to have keys that are most of the size of the record, with columns that are often null, zero, or contain values much smaller than the declared size of the column. There may be a situation during the merge phase of the sort when there's more than one copy of each record. Good luck, Ann [Non-text portions of this message have been removed]
RE: [firebird-support] Re: TempDirectories and ALTER INDEX ACTIVE
Alex, However, it sounds like rebuilding an index cannot require more space that the database size itself, right? Correct, in order to build the index, the engine must build and sort a projection of the index values. So, if you build an index on a string [say varchar(100)] column which is only sparsely populated (avg usage = 10 char) then it is reasonable/expected that the index will be much larger than the war data storage. Sean
