Re: [HACKERS] Oracle porting sample instr function
On Mon, Jul 2, 2012 at 8:51 PM, Greg Smith g...@2ndquadrant.com wrote: snip The INSTR implementation in the docs will instead search backwards from the end of the string if you tell it to start at 0, same as if you gave it a negative input. I think it's therefore possible to get the plpgsql version to return a value in cases Oracle would instead return 0. Seems like a straightforward thing to confirm and change the sample to do differently; just have to add an explicit test for a 0 value of beg_index. I wrote that sample eons ago with the plpgsql-porting doc. I probably overlooked the 0 behavior. Thanks for reporting Greg, and thanks Albe for providing a patch. Roberto -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Oracle porting sample instr function
On Wed, Jul 4, 2012 at 3:50 AM, Albe Laurenz laurenz.a...@wien.gv.at wrote: Robert Haas wrote: I can confirm that Oracle returns 0 if the third argument to INSTR is 0. Can someone provide a suitable doc patch? Thanks, committed. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Oracle porting sample instr function
Robert Haas wrote: I can confirm that Oracle returns 0 if the third argument to INSTR is 0. Can someone provide a suitable doc patch? Here you are. Yours, Laurenz Albe instr-doc.patch Description: instr-doc.patch -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Oracle porting sample instr function
Greg Smith wrote: A web site doc comment from user skong today points out a small issue around the sample INSTR function given in plpgsql-porting.html that I can't confirm (none of those dirty Oracle instances here today), but it sounds legit. A look at Oracle's documentation on the INSTR function at http://docs.oracle.com/cd/B28359_01/olap.111/b28126/dml_functions_1103.h tm says that the 3rd input, position to start searching, cannot be zero. skong says that Oracle will just return a 0 if you give it that invalid input. The INSTR implementation in the docs will instead search backwards from the end of the string if you tell it to start at 0, same as if you gave it a negative input. I think it's therefore possible to get the plpgsql version to return a value in cases Oracle would instead return 0. Seems like a straightforward thing to confirm and change the sample to do differently; just have to add an explicit test for a 0 value of beg_index. I can confirm that Oracle returns 0 if the third argument to INSTR is 0. Yours, Laurenz Albe -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Oracle porting sample instr function
On Tue, Jul 3, 2012 at 8:42 AM, Albe Laurenz laurenz.a...@wien.gv.at wrote: I can confirm that Oracle returns 0 if the third argument to INSTR is 0. Can someone provide a suitable doc patch? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
[HACKERS] Oracle porting sample instr function
A web site doc comment from user skong today points out a small issue around the sample INSTR function given in plpgsql-porting.html that I can't confirm (none of those dirty Oracle instances here today), but it sounds legit. A look at Oracle's documentation on the INSTR function at http://docs.oracle.com/cd/B28359_01/olap.111/b28126/dml_functions_1103.htm says that the 3rd input, position to start searching, cannot be zero. skong says that Oracle will just return a 0 if you give it that invalid input. The INSTR implementation in the docs will instead search backwards from the end of the string if you tell it to start at 0, same as if you gave it a negative input. I think it's therefore possible to get the plpgsql version to return a value in cases Oracle would instead return 0. Seems like a straightforward thing to confirm and change the sample to do differently; just have to add an explicit test for a 0 value of beg_index. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
