There's a clear GDBM garbage collection problem.
Can Unicon tell GDBM to collect garbage?

Here are some numbers.
I reran TAP with hoKeyType = concept.

    cd /home/knowledge/tap
    export KEDB=./db
    gdbmload --genus.species <genus.species.csv
    mke --noprompt <newtap.mkr 2>newtap.concept.err

The 2 GB hogenus.pag crash occurs at line 161986 of 216362 in newtap.mkr
Note that the newtap.hogenus.txt table dump is only 3 MB !
See more details below.

rhm@rhm8200 /home/knowledge/tap
$ mke --input "do dump od hogenus done;" >newtap.hogenus.txt
# hoKeyType = concept
$ mke --input "do dump od hovariable done;" >newtap.hovariable.txt
# hoKeyType = concept

$ cat newtap.hovariable.txt
hovariable[$nline] = 161986
hovariable[hoKeyType] = concept
hovariable[$hoindent] = 4
hovariable[$line] = MusicianChayanne isu Musician;
hovariable[$debug] = no

$ wc newtap*
      38      239     1528 newtap.concept.err
      28      210     1305 newtap.gs.err
   55488   166584  3325018 newtap.hogenus.txt
       5       17      166 newtap.hovariable.txt
  216362  1036071  9788873 newtap.mkr
  271921  1203121 13116890 total

$ mke --database
# hoKeyType = concept
DBDIR=./db
total 2214364
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hoact.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hoact.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hoattr.dir
-rwxr-xr-x 1 rhm None   81181605 Aug 22 06:33 hoattr.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hodef.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hodef.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hoflag.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hoflag.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:58 hogenus.dir
-rwxr-xr-x 1 rhm None 2147621590 Aug 22 06:33 hogenus.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hoiact.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hoiact.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hoinverse.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hoinverse.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hopart.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 hopart.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 horel.dir
-rwxr-xr-x 1 rhm None       3158 Aug 22 06:33 horel.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 hosynset.dir
-rwxr-xr-x 1 rhm None   35485052 Aug 22 06:33 hosynset.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:58 hovariable.dir
-rwxr-xr-x 1 rhm None    3129852 Aug 22 09:37 hovariable.pag
-rwxr-xr-x 1 rhm None       3072 Aug 22 05:59 ssdef.dir
-rwxr-xr-x 1 rhm None       3072 Aug 22 06:33 ssdef.pag

Dick McCullough
http://mkrmke.org