New post
AllAccepted answers
Mark Hanson · Aug 8, 2018

You are doing disk block reads in the one case which is why it is slower, how big is your global buffer pool? Also how big are your globals ^TestD and ^TEST2, use 'd ^%GSIZE' to find their sizes on disk. The $lb version will be slightly bigger as there is a byte taken as a type byte for each element and another length byte, this shows up when the data is very small like these single character ASCII elements, but $lb does mean you never need to worry about data that contains '#' characters and it preserves types where as the "a#b#..." format needs to convert everything into a string before storing it which adds runtime overhead too.

-- 

Mark

Mark Hanson · Mar 23, 2018

The behavior you are seeing is because of chain '.' handling of null objects. For example if you:

Set person=##class(Sample.Person).%New()

Write person.Name.AnythingYouLike

It will succeed and return "", but if you:

Set tmp=person.Name

Write tmp.AnythingYouLike

It will fail with an INVALID OREF error, as would 'Write (person.Name).AnythingYouLike'.

This behavior is inconsistent, so I will not defend it, but it is how the product works.

Mark Hanson · Jul 18, 2017

A few comments:

  • %ResultSet does have %Execute, %Next, %GetData, %Get, %Prepare methods also
  • In %ResultSet use 'Data' multidimentional property to get columns by name as this is more efficient than the 'Get' method.
  • In %SQL.StatementResult, do not use %Get to get columns by name, instead just reference the properties directly, e.g. 'Write resultOref.Name' instead of 'Write resultOref.%Get("Name")'
Mark Hanson · Apr 20, 2017

Streams support the idea of writing to them without changing the previous stream content so you can either accept the newly changed stream value or discard it depending on if you call %Save or not. In order to support this when you attach to an existing file and then append some data you are actually making a copy of the original file and appending data to this copy. When you %Save this we remove the original file and rename this copy so this is now the version you see. However as you can see making a copy of a file is a potentially expensive operation especially when the file gets large so using a stream here is probably not what you want.

As you just want to append the data and do not want file copies made I would just open the file directly in append mode (using either 'Open' command directly or %File class) and write the data you wish to append so avoiding stream behavior.

Mark Hanson · Mar 13, 2017

Can you provide the code you are using currently so we have something definitive to base comments off, but have you tried using $translate and reading the data in big chunks e.g. 16k at a time?

While 'binarystream.AtEnd {

  Set sc=outputstream.Write($translate(binarystream.Read(16000),badchars,goodchars)

}

Where binarystream is your binary input stream, outputstream is your output stream with the converted characters and badchars is a list of the bad characters you need to convert and goodchars is the list of the values you want the badchars converted into.

Mark Hanson · Mar 3, 2017

The biggest issue I saw is that when you call %Save() you are returning the Status code into variable 'Status' which is good, but then this variable is totally ignored. So if you save an object which does not for example pass datatype validation the %Save will return an error in the Status variable but the caller will never know the save failed or why the save failed.

In addition %DeleteId does not return an oref, it returns a %Status code, so you need to check this to see if it is reporting an error and report this to the caller if it does also.

Mark Hanson · Feb 10, 2017

Correct, the gateway will not cached files that are not served from 'always and cached'. Of course if you served a static file when this was set and then unset this then the gateway will still have it in its cache. Also the timeout value applies both to the browser timeout period and the CSP gateway timeout period.

You can also remove items from the gateway cache using code (which we do automatically when you edit a static file in Studio):

Set registry = $System.CSP.GetGatewayRegistry()

Set sc=registry.RemoveFilesFromCaches(remove)

See the class %CSP.Mgr.GatewayRegistry for more details of this method.