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Re: in_array performance in unsorted vs sorted array [message #178205 is a reply to message #178204]

Wed, 23 May 2012 12:16

Jerry Stuckle
Messages: 2598
Registered: September 2010

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Senior Member

On 5/23/2012 2:20 AM, William Gill wrote:
> I am reading transaction records from files. Each record has an
> alphanumeric GUID but that record may be repeated in more than one file
> (because of overlapping samples). I don't want to process duplicate
> records, so I am considering a simple flat file to store the GUID's of
> previously processed records.
>
> To keep things simple I plan to use $done=file() to read the flat file,
> and a simple if in_array to see if the current GUID has already been
> processed, if not process the current record and add its GUID to $done.
>
> Does anyone know if sorting an array has any significant impact on
> in_array, or can I simply push push values into $done?
>
> Also is there a better way than foreach() write() to get $done back into
> the flat file?
>

Arrays in PHP are associative; their keys are handled as hash values.
So I suspect it makes no difference on whether the array is sorted or not.

Also, what's wrong with foreach() write()? That's how you get arrays
back into a file. Ensure you lock the file so that you don't have two
scripts running against it at the same time.

But it sounds like you should be using a database. That would solve a
lot of your problems.

--
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Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
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[Message index]

		in_array performance in unsorted vs sorted array By: William Gill on Wed, 23 May 2012 06:20
		Re: in_array performance in unsorted vs sorted array By: Jerry Stuckle on Wed, 23 May 2012 12:16
		Re: in_array performance in unsorted vs sorted array By: William Gill on Wed, 23 May 2012 14:57
		Re: in_array performance in unsorted vs sorted array By: William Gill on Wed, 23 May 2012 15:01
		Re: in_array performance in unsorted vs sorted array By: Thomas Mlynarczyk on Thu, 24 May 2012 20:20
		Re: in_array performance in unsorted vs sorted array By: Captain Paralytic on Wed, 23 May 2012 09:36

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