How to translate show engine INNODB status?

I am transitioning from a programmer into DB and looking at this result looks like hieroglyphics to me. Can someone help me understand and read this result?

I executed the following code:

SHOW ENGINE INNODB STATUS;

and I got this result (please open it in pastebin)

https://drive.google.com/file/d/1n-8NEXz9xTt1dDG_w80vhes0Czg38V5c/view?usp=sharing

Thank you so much for your replies and I hope to learn so much from this community

Solution

Yep. It's hieroglyphics. I avoid it.

When it shows "the last deadlock", just look at the two queries -- that's the most important bit of info. Go find those queries in your code; see if you can speed them up and/or keep them out of each other's hair.

Your particular example ... Are you missing some COMMITs? What is the value of max_connections; sounds like it is ludicrously high. How fast are you repeating SHOW ENGINE STATUS;? Maybe so fast that it is stumbling over itself?

I see these:

SELECT  ID, groupid, FIELDTYPE, FIELD, FIELDID, OLDVALUE, OLDSTRING,
        NEWVALUE, NEWSTRING
    FROM  changeitem
    WHERE  (groupid IN (2148520, 2148521, 2148954, 2148955, 2148957,
                        2337772, 2694891) 
           )

Is there an index starting with groupid in changeitem?

UPDATE  userhistoryitem SET entitytype='Searcher', entityid='status',
        USERNAME='armine', lastviewed=1527555906745, data=null
    WHERE  ID=385440

Is ID the PRIMARY KEY of userhistoryitem?