RE: About rpm database

["Chowdhury, Chandan Dutta" <chandan-dutta chowdhury hp com>]

> -----Original Message-----
> From: Jeff Johnson [mailto:n3npq jbj gmail com] 
> Sent: Monday, May 29, 2006 8:32 PM
> To: RPM Package Manager
> Subject: Re: About rpm database
> 
> On 5/29/06, Chowdhury, Chandan Dutta 
> <chandan-dutta chowdhury hp com> wrote:
> > Hello All,
> >
> 
> First of all, an rpmdb is a hierarchical database using Berkeley DB.
> 
> > I have 2 questions for you
> >
> > 1. Can any one point me to a document describing the 
> structure of RPM 
> > database?
> > This what all tables are present in the RPM database, what 
> all columns 
> > in them.
> >
> 
> First of all, an rpmdb is a hierarchical database using Berkeley DB.
> So no SQL, no rows, no columns, no tables.
> 
> Headers are stored as blobs in /var/lib/rpm/Packages, the key 
> is a monotonically increasing integer. The current largest 
> values as retrieved and incremented in a RMW operation using 
> key = 0 whose value is the largest key in the rest of 
> Packages. The key for the header blob in Packages is known as 
> a "header instance".
> 
> All the other indices are inverted lists of certain tags 
> stored within a  header.
> That means that the value from the tag is used as a key to 
> retrieve a varibale length array of (header,element) indices. 
> In most cases, the element index is 0.
> 
> One can replace a Berkeley DB with sqlite3 for an rpmdb, but the
> rpm-4.4.2 that most vendors are choosing to distribute has 
> known problems with the implementation in 4.4.2.
> 
> > 2. Is there a CLI for doing SQL queries on the RPM db, if so plz 
> > provide me the link where I can find them.
> >
> 
> No SQL, the CLI for accessing an rpmdb is the --query mode of rpm.
> 
> Hint: Export all the data from an rpmdb for importing into 
> whatever SQL db you want by doing
>     rpm -qa --xml
> or
>     rpm -qa --qf '[%{*:xml}\n]'
> 
> 73 de Jeff
> 

Hello Jeff,

Thanks a lot for all the info on database. I was trying to understand
the whole structure of rpm and did not find any document describing the
database. Anyway thanks a lot for the usefull info. I will start playing
with the --xml option to rpm 

For sure if u have any other document on the database plz share it.

Thanks and Regards
Chandan