Hi Jack,
I'm glad to hear that the -t flag suggestion was helpful.
Typically, sqlca is just the name of a copy file, which contains additional source code for inclusion into your COBOL program. There is no need to separately compile sqlca. I believe you said you created sqlca.cbl by copying sqlca.cpy - this should not be necessary.
As you've noticed, when you add sqlca.cbl to the cob command, cob will treat it as a completely separate COBOL program, and compile it (just as any other .cbl file), creating a separate object file (.o) file for it. This (unnecessary) .o file would then be linked into the resulting shared object (.so) file, increasing the size of the resulting .so.