How to unzip journal file?

Question

Question

Lorenzo Scalese · Aug 7, 2023

#Databases #Journaling #InterSystems IRIS

Hi!

Currently, I'm working on a script using %SYS.Journal API.

My journal files are compressed, following the documentation the compression is zstd.

I tried to unzip a file with zstd tool, ex:

apt-get update
apt-get install zstd

zstd -d 20230806.001z -o 20230806.001

20230806.001z        : 92.03%   (909312 => 836859 bytes, 20230806.001)

Unfortunately, the unzipped file is invalid:

Write ##class(%SYS.Journal.File).IsValidJournal("/usr/irissys/mgr/journal/20230806.001")

The size of the unzipped file is greater than the compressed file, it's weird...

Is there a recommended tool to decompress a journal file?

%SYS.Journal API works fine with compressed files but I need to test the performance.

Maybe it's faster if the file is unzipped before (or not), that's the performance test I want to do.

Thank you!

Product version: IRIS 2023.2

$ZV: IRIS for UNIX (Ubuntu Server LTS for x86-64 Containers) 2023.2 (Build 202U) Thu May 18 2023 11:16:51 EDT

Discussion (2)1

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Mihoko Iijima · Aug 8, 2023

Hi @Lorenzo Scalese

How about Decompress() method in %SYS.Journal.File class?

set f1="C:\InterSystems\IRISHealth\mgr\journal\20230807.001z"
set f2="C:\InterSystems\IRISHealth\mgr\journal\test20230807.001"
write ##class(%SYS.Journal.File).Decompress(f1,f2)

And below method returns 1.

USER>Write ##class(%SYS.Journal.File).IsValidJournal(f2)
1

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score 1 · Answer 1 · 2023-08-08T03:00:57-04:00

Lorenzo Scalese · Aug 8, 2023

Hi @Mihoko Iijima!

I missed this method.

Thank you, It works!

1 0