Gives you access to one or more domains, relations, databases,
or record types and controls the access of other users to those
domains or databases. You can also use the READY command to ready
a domain or database again in order to change your access mode or
access option.
Format 1
READY domain-path-name [AT node-spec] [AS alias-1]
[ PROTECTED ] [ READ ]
[ ] [ WRITE ] [ CONSISTENCY ]
[ SHARED ] [ MODIFY ] [ CONCURRENCY ][,...]
[ EXCLUSIVE ] [ ] [ ]
[ EXTEND ]
[SNAPSHOT]
Format 2
READY database-path-name
[SNAPSHOT]
[PROTECTED ] [ READ ]
[ ] [ WRITE ] [ CONSISTENCY ]
[SHARED ] [ MODIFY ] [ CONCURRENCY ]
[EXCLUSIVE ] [ ] [ ]
[ EXTEND ]
[ { rdb-relation-name } ]
[USING { dbms-record-name } [ AS alias ] ]
[ { } ]
[ [SNAPSHOT] ]
[ ][,...]
[ [ PROTECTED ] [READ ] ]
[ [ ] [WRITE ] [CONSISTENCY ] ]
[ [ SHARED ] [MODIFY ] [CONCURRENCY ] ]
[ [ EXCLUSIVE ] [ ] [ ] ]
[ [EXTEND ] ]
1 – Arguments
domain-path-name
Is the dictionary path name of a domain to which you want access
or the domain table whose access option you want to change.
node-spec
Is the name of a node and an optional access control string.
A node name is a 1- to 6-character name that identifies the
location on the network. Examples are BIGSYS and LILSYS.
An access control string indicates a particular account on the
remote node. It consists of a user name, followed by one or more
blanks or tabs, a password, and an optional account name.
The following three node specifications are valid:
BIGSYS
BIGSYS"MORRISON RYLE"
BIGSYS"MORRISON RYLE KANT"
On DECnet links to some non-OpenVMS systems, you can use the UIC
number in place of the user name. For example:
BIGSYS"[240,240] RYLE"
BIGSYS"[240,240] RYLE KANT"
In the examples, the remote node is BIGSYS the user name is
MORRISON, the UIC is [240,240], the password is RYLE, and the
account name is KANT.
You can also use a prompting value expression to prompt the user
for the user name, password, account name, or UIC. Use single
quotation marks for the prompt string. For example:
DTR> READY CDD$TOP.DTR32.MORRISON.YACHTS AT
CON> BIGSYS"*.'username' *.'password'"
Enter username: MORRISON
Enter password:
DTR>
alias
Is a name you use if you include the AS clause in the READY
command to refer to the domain, relation, or Oracle CODASYL DBMS
record specified. You use the alias in place of the given name
of the domain, relation, or Oracle CODASYL DBMS record where the
syntax of a statement calls for that domain, relation, or Oracle
CODASYL DBMS record name. If you are using an alias for a domain
name, do not use the alias in full or relative dictionary path
names.
database-path-name
Is the Oracle CDD/Repository path name defined for the DEC
DATATRIEVE definition of the Oracle CODASYL DBMS, Oracle Rdb,
VAX Rdb/ELN, or DEC DB Integrator Gateway database, or for the
relational database definition created by Oracle Rdb. It can also
be a CDD$DATABASE object. If you ready a Oracle CODASYL DBMS or
relational database without specifying any relation or record
names, DEC DATATRIEVE readies all relations or records in the
database. READY accepts both DMU and CDO style path names.
relation-name
Is the name assigned to the relation when the relational
database was created. The relation name can be the name of a
view relation.
record-name
Is the name assigned to the Oracle CODASYL DBMS record when the
database was created.
SNAPSHOT
Are the options you can select to control the access of other
users to a domain, relation, or Oracle CODASYL DBMS record you
ready. The specific constraints are explained in Access Options:
Table 1-6 Access Options
Option Access Constraints
SNAPSHOT SNAPSHOT is a READ access for databases that takes a
"picture" of the database when it is readied. In order
to have SNAPSHOT access, all relations or records
pertaining to the database must be readied with
SNAPSHOT access. Any other user can access the same
database with any access mode and option. In general,
you do not see other users' changes until the end
of the transaction. If you use SNAPSHOT with another
option, such as CONCURRENCY, you may see other users'
changes, depending on the database system. SNAPSHOT is
the default for relational databases, relations, and
domains based on relational sources.
PROTECTED Any other user can have only READ access to records in
the domain or relation. No other user can have WRITE,
MODIFY, or EXTEND access to the records in the domain
or relation. This option is the default for domains
containing records from RMS files and for all view
domains.
SHARED Any other user can have access to the domain,
database, relation, or Oracle CODASYL DBMS record
at the same time, in any access mode. This option
is the default for Oracle CODASYL DBMS domains,
Oracle CODASYL DBMS databases, and Oracle CODASYL
DBMS records.
EXCLUSIVE No other user can have access to the domain, database,
relation, or Oracle CODASYL DBMS record at the same
time, in any access mode. If the domain is based on
a RMS file, the file containing the data is locked by
RMS.
READ
Are the options you can select to request a mode of access to a
domain, database, relation, or Oracle CODASYL DBMS record. When
using Format 1, whether you get that mode of access is determined
by privileges assigned to you in the access control list of the
domain. When using Format 2, whether you get that mode of access
is determined by privileges assigned to you in the access control
list of the database definition.
When you are using either Format 1 or Format 2 and you are
accessing a Oracle CODASYL DBMS or relational database, you must
also have appropriate privileges in the Oracle CODASYL DBMS,
Oracle Rdb or VAX Rdb/ELN access control lists to request the
access mode you select. For Oracle CODASYL DBMS, you need access
to the schema, subschema, record and DEC DATATRIEVE database
definitions in the data dictionary.
CONSISTENCY
Are the options you can select to determine whether you can
see changes made by other users to the data you are accessing.
CONSISTENCY guarantees that while you are accessing data, you do
not see updates made by other users.
CONCURRENCY allows you to see other users' updates to the data
you are accessing.
CONSISTENCY is the DEC DATATRIEVE default for the first ready of
a relational source.
Once you specify CONSISTENCY or CONCURRENCY, that option becomes
the default until you change the option in a subsequent ready or
you finish the database.
Multi-User Access to Domains Based on RMS Files summarizes the
effects of various combinations of access options and access
modes for domains based on RMS files.
Table 1-7 Multi-User Access to Domains Based on RMS Files
Another User Your
Can Then Effect
You Ready a Ready the on Other
Domain Domain Users Other Users'Effect on You
EXCLUSIVE No access. No one No effect.
READ else can
EXCLUSIVE read the
WRITE file.
PROTECTED PROTECTED No one No effect.
READ READ else can
SHARED READ write
to the
file.
PROTECTED SHARED READ No one No effect.
WRITE else can
write
to the
file.
SHARED READ PROTECTED No one Users with WRITE access
READ with may change records you are
PROTECTED WRITE reading or have read.
WRITE access
SHARED READ can
SHARED WRITE select
your
selected
record.
SHARED WRITE SHARED READ No one You cannot write to the
SHARED WRITE else can selected record of any
modify other user. You cannot
your write to the target record
selected of a MODIFY or ERASE
record statement entered by
or the a SHARED WRITE user. A
target SHARED WRITE user can also
record write to a record you have
of your just modified.
MODIFY
or ERASE
state-
ment.
You can
modify a
record
another
user
has just
modi-
fied.
When two applications try to access the same domain based on a
RMS file, RMS may lock a record that DEC DATATRIEVE needs to
access. DEC DATATRIEVE then tries for 12 seconds to access the
record. At the end of this period, DEC DATATRIEVE takes one of
two actions, depending on whether SET LOCK_WAIT is in effect.
o If SET NO LOCK_WAIT is in effect, you receive an RMS$_RLK
message: "Target record currently locked by another stream."
Then DEC DATATRIEVE aborts the statement. SET NO LOCK_WAIT is
the default.
o If SET LOCK_WAIT is in effect, DEC DATATRIEVE turns control
over to RMS to wait for the record. You cannot use CTRL/C
to cancel the wait. RMS waits until the record is released,
or, in case of deadlock, you receive the RMS deadlock error
message.
The LOCK_WAIT setting applies to all sources, including Oracle
CODASYL DBMS and relational databases which are readied after the
SET LOCK_WAIT command is issued. NO LOCK_WAIT was selected as the
default for DATATRIEVE because it is the RMS default. However,
NO LOCK_WAIT is not always the recommended mode for relational
access. LOCK_WAIT is required for DEC DB Integrator Gateway.
Multi-User Access to Oracle CODASYL DBMS, Oracle Rdb, and VAX
Rdb/ELN Sources summarizes the effects of various combinations of
access options and access modes for Oracle CODASYL DBMS domains
and Oracle Rdb or VAX Rdb/ELN domains and relations.
Table 1-8 Multi-User Access to Oracle CODASYL DBMS, Oracle Rdb,
and VAX Rdb/ELN Sources
Another
You Ready User Can
a Domain, Then Ready
Database, the Domain,
Relation, Database, Your
Oracle Oracle Effect
CODASYL CODASYL on Other
DBMS Record DBMS Record Users Other Users' Effect on You
EXCLUSIVE No access. No one No effect.
READ else can
EXCLUSIVE read the
WRITE realm
or rela-
tion.
PROTECTED PROTECTED No one No effect.
READ READ else can
SHARED READ write
to the
realm
or rela-
tion.
PROTECTED SHARED READ No one You may encounter read
WRITE else can locks other users have put
write on a record when you try
to the to modify it.
realm
or re-
lation.
Other
users
may en-
counter
write
locks
during
your
transac-
tion.
SHARED READ PROTECTED A SHARED You may encounter write
READ WRITE locks during another
PROTECTED user user's transaction.
WRITE may have
SHARED READ to wait
SHARED WRITE until
you
release
your
read
locks.
SNAPSHOT for With any No You do not see changes
Oracle Rdb access and effect other users make to the
or VAX Rdb mode. on database until a COMMIT or
/ELN domains users. ROLLBACK is performed.
and Oracle
CODASYL DBMS
records
SHARED WRITE SHARED READ Other You may encounter read and
SHARED WRITE users write locks during another
may en- user's transaction.
counter
read and
write
locks
during
your
transac-
tion.
2 – Examples
The following example readies the domain YACHTS for WRITE access:
DTR> READY YACHTS WRITE
The following example readies the domain PHONES for EXTEND
access:
DTR> READY PHONES (*) EXTEND
Enter password for PHONES:
DTR>
The following example defines a domain with the prompt built
into the domain definition. DEC DATATRIEVE does not display the
password:
DTR> DEFINE DOMAIN PROMPT_YACHTS USING YACHT(*) ON YACHT;
DTR> READY PROMPT_YACHTS AS PYTS
Enter password for YACHT:
DTR>
The following example readies the relations EMPLOYEES and SALARY_
HISTORY in the Oracle Rdb database PERSONNEL for SNAPSHOT access:
DTR> READY PERSONNEL USING EMPLOYEES, SALARY_HISTORY
DTR>
The following example readies the SALARY_HISTORY relation in the
Oracle Rdb database PERSONNEL for SHARED WRITE access with the
CONCURRENCY option:
DTR> READY PERSONNEL SHARED WRITE USING SALARY_HISTORY CONCURRENCY
The following example readies the Oracle CODASYL DBMS domain
VENDORS for the default access mode SHARED READ:
DTR> READY VENDORS
DTR>