damage to pkg's sqlite data base

[Scott Bennett]

     For nearly two weeks I've been stymied by an apparently damaged record
in the sqlite data base used by pkg(8) and pkg-static(8).  Unfortunately,
it is a record for a port that is depended upon rather heavily, lang/gcc.
lang/gcc compiled and linked just fine, but any attempt to install the result
ends up like this.

===>  Checking if gcc already installed
===>   Registering installation for gcc-4.8.4_3
Installing gcc-4.8.4_3...
pkg-static: sqlite error while executing iterator in file pkgdb_iterator.c:931: database disk image is malformed
pkg-static: sqlite error while executing INSERT OR REPLACE INTO files (path, sha256, package_id) VALUES (?1, ?2, ?3) in file pkgdb.c:1722: database disk image is malformed
*** Error code 70

Stop.
make: stopped in /usr/ports/lang/gcc

     I'm not familiar with sqlite commands, nor with the structure of the
pkg data base, nor any of several other relevant topics.  But I do have
questions:

	1) how might the damage have happened?

	2) how might such an event be avoided/prevented in the future?

	3) most urgently, how can I *fix* it?

	4) I was unable to find any instructions for recreating a pkg data
	base if the data base gets damaged/destroyed.  Is there a way to
	do that that I missed?

     Thanks again for any help here.


                                  Scott Bennett, Comm. ASMELG, CFIAG
**********************************************************************
* Internet:   bennett at sdf.org   *xor*   bennett at freeshell.org  *
*--------------------------------------------------------------------*
* "A well regulated and disciplined militia, is at all times a good  *
* objection to the introduction of that bane of all free governments *
* -- a standing army."                                               *
*    -- Gov. John Hancock, New York Journal, 28 January 1790         *
**********************************************************************