Q: When performing a summarize I get error: "Fatal error: Out of memory (allocated ***) (tried to allocate 40 bytes) in /xxxxxxxxx/xx/xxxxxxxxxx/xxxxxx/mysite/includes/data_base_.php on line LLL."
A: If your com_joomlastats is below version 2.2.1 then upgrade to 2.2.1 and try again.
If your com_joomlastats is 2.2.1 or above then:
look in file admin.joomlastats.html.php search for function DoSummariseTask() and lower value 10000 in line
by 1000. If you still get the error message, then lower again with 1000, until you reach 1000.
user ato33 was able to do the summarization with a value of 5000. Please report back here what value worked for you.