Re: [firebird-support] Blob write to Embedded on Linux performance
Am 28.05.2014 11:38, schrieb Mike Ro miker...@gmail.com [firebird-support]:
I am sorry to bump this, but has anyone else got experience of using
blobs on Linux?
Yes, of course, but I never felt the need to time the operations, we
are using a udf s.th. like:
void EXPORT fn_b_load ( char* s , BLOB b )
{
unsigned char *buffer;
if ( b-blob_handle )
{
int buffsize = 4096;
FILE *file;
unsigned char *fname = intern_recode(s);
file= fopen ( fname, rb );
if ( file )
{
buffer= ( unsigned char * ) malloc ( buffsize );
if ( buffer )
{
int readSize;
for ( ;; )
{
readSize = fread ( buffer,1,buffsize, file );
( *b-blob_put_segment ) ( b-blob_handle, buffer,readSize );
if ( readSize != buffsize )
break;
}
free ( buffer );
}
fclose ( file );
}
free( fname);
}
}
to load documents into the database.
I will try to find the time to check thiswith some big mp3's.
fsg
--
Fascinating creatures, phoenixes, they can carry immensely heavy loads,
their tears have healing powers and they make highly faithful pets.
- J.K. Rowling
Re: [firebird-support] Blob write to Embedded on Linux performance
On 02/06/2014 12:06, Frank Schlottmann-Gödde fr...@schlottmann-goedde.de [firebird-support] wrote: I am sorry to bump this, but has anyone else got experience of using blobs on Linux? Yes, of course, but I never felt the need to time the operations, we are using a udf ... to load documents into the database. I will try to find the time to check this with some big mp3's. Frank, many thanks for your response, example UDF and testing. I will certainly try to implement the UDF later today. Yesterday I tried the same IBPP code on Windows 8 and it is much faster for files ~10Mb in size, but I also tested 500Mb video and performance was similar to Linux at that size. As well as my IBPP code, I also tested FlameRobin, Database Workbench and FSQL on Windows all with broadly similar results. Unfortunately apart from FlameRobin I couldn't find any simple way to load a blob on Linux, so your UDF will be a good comparison for me to make. I found this interesting blog but unfortunately the code linked to is no longer available. http://codicesoftware.blogspot.com/2008/09/firebird-is-faster-than-filesystem-for.html Thanks againMike
Re: [firebird-support] Update only changed tuple/ execute if-statement via execute statement?
Thank you very much for your arguments/tips. Pity that there is no more perfomant general trigger - approach. But recreating triggers - maybe over stored procedures - is also a possibility for me. Thank you. Eric 2014-05-30 17:08 GMT+02:00 Ann Harrison aharri...@ibphoenix.com [firebird-support] firebird-support@yahoogroups.com: On Sat, May 24, 2014 at 8:51 AM, eric wulfhekel eric.wulfhe...@gmail.com [firebird-support] firebird-support@yahoogroups.com wrote: I want to create a update trigger which sets the current date to a field modified if values has changed. I have a lot of tables with a lot of columns so i want to work with system table for that task. I build the if-statement within a select and wat to execute this statement I've left your example below. You're on the right track. The actual problem you're having is that EXECUTE STATEMENT executes SQL statements. You're generating a statement that can be used only in triggers and stored procedures. As Set suggested, a better plan would be to use your current approach, but generate actual CREATE TRIGGER statements rather than the PSQL. Yes, that means that you will need to recreate triggers when your tables change, but you may be able to do that - or at least signal that maintenance is required - with a DDL trigger. Alternately you could generate a series of SQL statements - UPDATE ... WHERE NEW.field IS DISTINCT FROM OLD.field - and execute them. However, that would be horribly inefficient - searching the system tables, generating a query, passing that query to the engine where it has to be parsed, compiled, optimized, executed, and released - all of that for every field in every record you change. I'd bet that performance would be measured not by wall clock, but by calendar. Good luck, Ann Here's the statement you tried and the error... CREATE TRIGGER PLZTEST_MODIFIED FOR PLZTEST ACTIVE BEFORE UPDATE POSITION 0 AS declare variable stmt varchar(1024); begin for select 'if (new.' || rdb$field_name || ' is null and old.' || rdb$field_name || ' is not null or new.' || rdb$field_name || 'is not null and old.' || rdb$field_name || ' is null or new.' || rdb$field_name || ' old.' || rdb$field_name || ') then new.MODIFIED = current_timestamp;' from rdb$relation_fields where rdb$relation_name = 'PLZTEST' into :stmt do execute statement stmt; end The resulting statement looks good. The problem here seems, that i could not execute statements starts with if. the error occur is Dynamic SQL Error. SQL error code = -104. Token unknown - line 1, column 1. if. Or maybe is there another way to realise that? Thank you in advance
[firebird-support] Select...Join Query
If this is possible in a single query, could you please show me to return the 'select'-ed column value in the example below, whether or not the FK condition is satisfied. In following sample query, TableTwo is related to TableOne via foreign key relationship): Select kOne, apples from TableOne join TableTwo on FKone = kOne. Best, jwc
[firebird-support] INSERT .. RETURNING not returning any record when using ADO .NET Provider
Hello all We are running Firebird on a Cubox (ARM device) with Ubuntu 10.4. I'm using the ADO.NET Provider installed via NuGet and almost everything works as it should. I'm developing cross-SQL ORM and I've been using the RETURNING statement to retrieve the ID (or other trigger-generated values) of a newly inserted row. This works like a charm on Oracle and MSSQL but in Firebird the RETURNING statement doesn't return anything. The documentation says: In DSQL, a statement with a RETURNING clause always returns exactly one row. If no record was actually inserted, the fields in this row are all NULL. This behaviour may change in a later version of Firebird. In PSQL, if no row was inserted, nothing is returned, and the receiving variables keep their existing values. No record is returned. I found this bug report http://tracker.firebirdsql.org/browse/DNET-319 which seems to describe my problem, but it was reported 4 years ago and apparently not yet solved. Is there any way for me to get around this issue without having to fix and build the code myself, as suggested in the bug report comments? Best Regards Mikkel Nygaard
SV: [MULIG SPAM] [firebird-support] Select...Join Query
If this is possible in a single query, could you please show me to return the 'select'-ed column value in the example below, whether or not the FK condition is satisfied. In following sample query, TableTwo is related to TableOne via foreign key relationship): Select kOne, apples from TableOne join TableTwo on FKone = kOne. Hi Jack, if the answer is not simply adding the word 'left' or 'right', then I don't understand your question. Hence, if not Select kOne, apples from TableOne left join TableTwo on FKone = kOne or Select kOne, apples from TableOne right join TableTwo on FKone = kOne is the answer you're looking for, then please rephrase your queston. HTH, Set
