That's good to know. I searched the internet and found a page about implementing dynamic arrays in C and he was using "double", but 1.5 also sounds reasonable. I wonder if perhaps there should be some sort of ratcheting down as the number of rows gets very large.
________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of David Crayford <dcrayf...@gmail.com> Sent: Thursday, August 4, 2016 8:41 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: COBOL 2014 dynamic capacity tables On 4/08/2016 2:52 AM, Frank Swarbrick wrote: > Even in the case where it does increase the actual allocated capacity, it > does not do it "one row at a time". Rather, it doubles the current physical > capacity and "reallocates" (using CEECZST) the storage to the new value. > This may or may not actually cause LE storage control to reallocate out of a > different area (copying the existing data from the old allocated area). If > there is enough room already it does nothing except increase the amount > reserved for your allocation. And even then, LE has already allocated a > probably larger area prior to this from actual OS storage, depending on the > values in the HEAP runtime option. Almost all the dynamic array implementations that I'm aware of, C++ std::vector, Java ArrayList, Python lists, Lua tables, use a growth factor of 1.5. Apparently it's a golden ratio. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
