Re: MUMPS in lisp?
- From: George Neuner <gneuner2/@/comcast.net>
- Date: Sun, 20 Jan 2008 02:04:37 -0500
On Sun, 20 Jan 2008 05:45:03 +0000, vanekl <vanek@xxxxxxx> wrote:
George Neuner wrote:
On Fri, 18 Jan 2008 16:52:05 -0800 (PST), gavino <gavcomedy@xxxxxxxxx>...
wrote:
Lisp already has implementations of and interfaces to virtually every
type of database that exists. Though I can't find a hierarchical
database (as in MUMPS) searching just now, I'm sure that one or more
exist somewhere.
George
--
for email reply remove "/" from address
postgresql allows for hierarchical table structures, and lisp has an interface
(i think it's called pg, IIRC).
Postgres's hierarchical tables aren't quite the same. In MUMPS the
table itself is a 2 dimensional linked list structure:
tables
|- table1
|------- col1 - col2 - ... - coln
| | | |
|- rec1 - <data 1,1> - <data 1,2> - ... - <data 1,n>
| | | |
|- rec2 - <data 2,1> - <data 2,2> - ... - <data 2,n>
| | | |
|- :
| | | |
|- recm - <data m,1> - <data m,2> - ... - <data m,n>
A record is a linked list of disk pages containing field data. Each
data item is also linked into a separate list headed by attribute.
Several fields may share a page so the links between them are of the
form page#:offset rather than a more typical file offset to the item.
MUMPS is really a network database (in the DB topology meaning of
"network" ... not the LAN/WAN meaning) which happens to impose a
hierarchical organization rather than allow a more general graph
structure.
George
--
for email reply remove "/" from address
.
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- From: gavino
- Re: MUMPS in lisp?
- From: George Neuner
- Re: MUMPS in lisp?
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