a) there are several articles in the Palm Knowledge Base (two of which are
1748 and 1145) that outline memory usage in the Palm OS
b) >From my earlier post:
>Both OS versions (OS2.x and 3.0)have a DB overhead of 84 bytes
>Both OS versions allocate DB memory in 4 byte chunks (so a record of 2
bytes
>will have an actual size of 4)
>Here's where they differ:
>OS 2.x has a record overhead of 14 bytes so my record of a UINT, INT and 2
>floats (4+ 2 + 8 + 8 = 22 bytes / 4 = 5.5 =>24bytes) will have a record
size
>of 38 bytes
>OS 3.x has a record overhead of 16 bytes so my record of a UINT, INT and 2
>floats (4+ 2 + 8 + 8 = 22 bytes / 4 = 5.5 =>24bytes) will have a record
size
>of 40 bytes
>My DB with 2 records in OS 2.0 is 84 (DB Overhead) + 2 * 38 = 160 bytes
>In OS 2.0 with 2 records is 84 + 2*40 = 164 bytes
>the header size will vary between OS releases and the best
>way to determine that is through experimentation. Additionally, the memory
>manager may add 0-7 bytes to the end of the record to pad the data so it
>stays in byte multiples. I found that the current magic number is 4 bytes.
>(i.e. all records are allocated in multiples of 4 bytes)
>Dave Fedor told me that prior to OS 3.0, the memory manager had a 6 byte
>overhead per record and after 3.0 it became 8 bytes. He also said all DB
>memory is allocated in 4 byte multiples.
>So, your DB size will be = (DB header overhead + (record size normalized to
>4 byte chunks + record overhead)*number records)
>I found the DB overhead to be 84 bytes for both 2.x and 3.0
-----Original Message-----
From: Nicholas Breau <[EMAIL PROTECTED]>
Newsgroups: palm-dev-forum
To: Palm Developer Forum <[EMAIL PROTECTED]>
Date: Friday, April 07, 2000 1:46 PM
Subject: Database size in a PALM
>Is their a way to easily determine the amount of RAM available in a PALM ?
>I have a database with 120,000 records and I was wondering how I could find
>out if they could fit on a PALM. I know it depends on the size of each
>record, but was wondering if anybody could let me know how I could
determine
>a rough estimate.
>
>thanks for your help.
>Nick.
>
>
>
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