(VERY) Slow Query - PostgreSQL 9.2

Hi all,

I'm trying to get the query below a better performance.. but just don't
know what else I can do...

Please, have a look and let me know if you can help somehow.. also.. if you
need some extra data jet ask me please.

* Note that the gorfs.inode_segments table is 1.7TB size

I have the following Query:

explain analyzeSELECT split_part(full_path, '/', 4)::INT AS account_id,
split_part(full_path, '/', 6)::INT AS note_id,
split_part(full_path, '/', 9)::TEXT AS variation,
st_size,
segment_index,
reverse(split_part(reverse(full_path), '/', 1)) as file_name,
i.st_ino,
full_path,
(i.st_size / 1000000::FLOAT)::NUMERIC(5,2) || 'MB' AS
size_mbFROM gorfs.inodes iJOIN gorfs.inode_segments s
ON i.st_ino = s.st_ino_targetWHERE
i.checksum_md5 IS NOT NULL
AND s.full_path ~ '^/userfiles/account/[0-9]+/[a-z]+/[0-9]+'
AND i.st_size > 0;
split_part(s.full_path, '/', 4)::INT IN (
SELECT account.id
FROM public.ja_clients AS account
WHERE
NOT (
((account.last_sub_pay > EXTRACT('epoch' FROM
(transaction_timestamp() - CAST('4 Months' AS INTERVAL)))) AND
(account.price_model > 0)) OR
(account.regdate > EXTRACT('epoch' FROM
(transaction_timestamp() - CAST('3 Month' AS INTERVAL)))) OR
(((account.price_model = 0) AND (account.jobcredits >
0)) AND (account.last_login > EXTRACT('epoch' FROM
(transaction_timestamp() - CAST('4 Month' AS INTERVAL)))))
) LIMIT 100);

- Explain analyze link: http://explain.depesz.com/s/Oc6

The query is taking ages, and I can't get the problem solved.

These are the index I've already created on the inode_segments table:

Indexes:
"ix_account_id_from_full_path" "btree"
(("split_part"("full_path"::"text", '/'::"text", 4)::integer)) WHERE
"full_path"::"text" ~
'^/userfiles/account/[0-9]+/[a-z]+/[0-9]+'::"text"
"ix_inode_segments_ja_files_lookup" "btree" ((CASE
WHEN "full_path"::"text" ~ '/[^/]*\.[^/]*$'::"text" THEN
"upper"("regexp_replace"("full_path"::"text", '.*\.'::"text",
''::"text", 'g'::"text"))
ELSE NULL::"text"END)) WHERE
"gorfs"."is_kaminski_note_path"("full_path"::"text")
"ix_inode_segments_notes_clientids" "btree"
(("split_part"("full_path"::"text", '/'::"text", 4)::integer)) WHERE
"gorfs"."is_kaminski_note_path"("full_path"::"text")
"ix_inode_segments_notes_clientids2" "btree" ("full_path")
"ix_inode_segments_notes_fileids" "btree"
(("split_part"("full_path"::"text", '/'::"text", 8)::integer)) WHERE
"gorfs"."is_kaminski_note_path"("full_path"::"text")
"ix_inode_segments_notes_noteids" "btree"
((NULLIF("split_part"("full_path"::"text", '/'::"text", 6),
'unassigned'::"text")::integer)) WHERE
"gorfs"."is_kaminski_note_path"("full_path"::"text")

These are the index I've already created on the inodes table:

Indexes:
"ix_inodes_checksum_st_size" "btree" ("checksum_md5", "st_size")
WHERE "checksum_md5" IS NOT NULL

*Question:*

What else can I do to improve the Performance of the Query?