overidx: document column uses

This may be useful for keeping our heads on straight dealing
with IMAP, NNTP, JMAP, etc.

diff --git a/lib/PublicInbox/OverIdx.pm b/lib/PublicInbox/OverIdx.pm
index 6f0477f0a7150587e4b64a0bf0470736b8caba75..db4b7738dfd602b339072bd8d7b6db31d7e71a54 100644 (file)
--- a/lib/PublicInbox/OverIdx.pm
+++ b/lib/PublicInbox/OverIdx.pm
@@ -379,12 +379,12 @@ sub create_tables {
 
        $dbh->do(<<'');
 CREATE TABLE IF NOT EXISTS over (
-       num INTEGER NOT NULL,
-       tid INTEGER NOT NULL,
-       sid INTEGER,
-       ts INTEGER,
-       ds INTEGER,
-       ddd VARBINARY, /* doc-data-deflated */
+       num INTEGER NOT NULL, /* NNTP article number == IMAP UID */
+       tid INTEGER NOT NULL, /* THREADID (IMAP REFERENCES threading, JMAP) */
+       sid INTEGER, /* Subject ID (IMAP ORDEREDSUBJECT "threading") */
+       ts INTEGER, /* IMAP INTERNALDATE (Received: header, git commit time) */
+       ds INTEGER, /* RFC-2822 sent Date: header, git author time */
+       ddd VARBINARY, /* doc-data-deflated (->to_doc_data, ->load_from_data) */
        UNIQUE (num)
 )
 
@@ -406,13 +406,13 @@ CREATE TABLE IF NOT EXISTS counter (
        $dbh->do(<<'');
 CREATE TABLE IF NOT EXISTS subject (
        sid INTEGER PRIMARY KEY AUTOINCREMENT,
-       path VARCHAR(40) NOT NULL,
+       path VARCHAR(40) NOT NULL, /* SHA-1 of normalized subject */
        UNIQUE (path)
 )
 
        $dbh->do(<<'');
 CREATE TABLE IF NOT EXISTS id2num (
-       id INTEGER NOT NULL,
+       id INTEGER NOT NULL, /* <=> msgid.id */
        num INTEGER NOT NULL,
        UNIQUE (id, num)
 )
@@ -423,7 +423,7 @@ CREATE TABLE IF NOT EXISTS id2num (
 
        $dbh->do(<<'');
 CREATE TABLE IF NOT EXISTS msgid (
-       id INTEGER PRIMARY KEY AUTOINCREMENT,
+       id INTEGER PRIMARY KEY AUTOINCREMENT, /* <=> id2num.id */
        mid VARCHAR(244) NOT NULL,
        UNIQUE (mid)
 )