Lob locators

Claim 3

The method of claim 1 wherein the step of sending the client a first set of data is performed by sending the client a first set of data that does not include any LOB data from the LOB that belongs in the LOB column of the row.

Claim 4

The method of claim 1 wherein the step of sending the client the first set of data is performed without the server storing state information that indicates that the client was sent the first set of data.

Claim 5

The method of claim 3 further comprising the steps of: the server determining whether the client has permission to perform the operation on the LOB in response to the client requesting the server to perform the operation on the LOB; and the server storing state information that indicates whether the client has permission to perform the operation on the LOB in response to determining that the client has permission to perform the operation on the LOB.

Claim 6

The method of claim 1 wherein: the step of receiving from a client of said one or more clients a command that specifies a row of a table includes receiving from the client a command that specifies a row in a view that includes data from the table; and the locator for the LOB includes data that identifies the view.

Claim 7

The method of claim 5 further comprising the step of the server determining whether the client has permission to perform the operation by reading from the locator the data that identifies the view and inspecting permissions associated with the view.

Claim 8

The method of claim 1 wherein: the LOB was selected from a view; and before sending said first set of data to said client, the server performs the steps of: generating a check value based on one or more values stored in said locator; and storing the check value in the locator.

Claim 9

The method of claim 7 wherein, after receiving the locator from the client, the server performs the steps of: reading said one or more values and said check value from said locator; determining whether said check value is a valid check value for said one or more values; and said server performing said operation only if said check value is a valid check value for said one or more values.

Claim 10

The method of claim 7 wherein the step of generating a check value based on one or more values includes generating a check value based on a view identifier that identifies a view through which said client is attempting to access said LOB.

Claim 11

The method of claim 1 wherein: the table resides in a database; and the server stores the LOB outside of the database.

Claim 12

The method of claim 1 wherein: the table resides in a database; the server stores the LOB within the database, but outside of the table within which the LOB belongs.

Claim 13

The method of claim 1 wherein: the table resides in a database; the server stores the LOB within the database and inside of the table within which the LOB belongs.

Claim 14

The method of claim 1 wherein: the table resides in a database; the LOB is stored at a particular location outside the database; the server establishes a mapping between an alias and the particular location; and the server stores in the locator the alias before sending said first set of data to said client.

Claim 15

A computer-readable medium carrying one or more sequences of one or more instructions for performing operations on large objects (LOBs) in a database system that includes a server and one or more clients, the one or more sequences of one or more instructions including instructions which, when executed by the server, cause the server to perform the steps of: the server receiving from a client of said one or more clients a command that identifies a row of a table, wherein the table includes a LOB column that contains LOBs; the server responding to the command by sending the client a first set of data that includes a locator for a LOB that belongs in the LOB column of the row; wherein said locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; the server receiving a request from the client to perform an operation on the LOB, wherein the operation does not modify the LOB, the request passing the locator for the LOB to a routine provided by the server; and the server performing the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.

Claim 16

A computer-readable medium carrying one or more sequences of one or more instructions for performing operations on large objects (LOBs) in a database system that includes a server and one or more clients, the one or more sequences of one or more instructions including instructions which, when executed by the server, cause the server to perform the steps of: the server receiving from a client of said one or more clients a command that identifies a row of a table, wherein the table includes a LOB column that contains LOBs; the server responding to the command by sending the client a first set of data that includes a locator for a LOB that belongs in the LOB column of the row; wherein said locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; the server receiving a request from the client to perform an operation on the LOB, wherein the operation does not modify the LOB, the request passing the locator for the LOB to a routine provided by the server; and the server performing the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.

Claim 17

The computer-readable medium of claim 14 wherein the step of sending the client a first set of data is performed by sending the client a first set of data that does not include any LOB data from the LOB that belongs in the LOB column of the row.

Claim 18

The computer-readable medium of claim 14 wherein the step of sending the client the first set of data is performed without the server storing state information that indicates that the client was sent the first set of data.

Claim 19

The computer-readable medium of claim 16 further comprising one or more sequences of one or more instructions which, when executed by the server, cause the server to perform the steps of: the server determining whether the client has permission to perform the operation on the LOB in response to the client requesting the server to perform the operation on the LOB; and the server storing state information that indicates whether the client has permission to perform the operation on the LOB in response to determining that the client has permission to perform the operation on the LOB.

Claim 20

The computer-readable medium of claim 14 wherein: the step of receiving from a client of said one or more clients a command that specifies a row of a table includes receiving from the client a command that specifies a row in a view that includes data from the table; and the locator for the LOB includes data that identifies the view.

Claim 21

The computer-readable medium of claim 18 further comprising one or more sequences of one or more instructions which, when executed by the server, cause the server to perform the step of determining whether the client has permission to perform the operation by reading from the locator the data that identifies the view and inspecting permissions associated with the view.

Claim 22

The computer-readable medium of claim 14 further comprising one or more sequences of one or more instructions which, when executed by the server, cause the server to perform the following steps before sending said first set of data to said client if the LOB was selected from a view: generating a check value based on one or more values stored in said locator; and storing the check value in the locator.

Claim 23

The computer-readable medium of claim 20 further comprising one or more sequences of one or more instructions which, when executed by the server, cause the server to perform the following steps after receiving the locator from the client if the LOB was selected from a view: reading said one or more values and said check value from said locator; determining whether said check value is a valid check value for said one or more values; and said server performing said operation only if said check value is a valid check value for said one or more values.

Claim 24

A database system comprising: one or more computer systems coupled to allow communication between processes executing on said one or more computer systems; a client executing on at least one of said one or more computer systems; a server executing on at least one of said one or more computer systems; said client being configured to: send a command that identifies a row in a table to a server, wherein the table includes a LOB column that contains LOBs; receive from the server a first set of data that includes a locator for a LOB that belongs in the LOB column of the row; wherein said locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; and request the server to perform an operation on the LOB by passing the locator for the LOB to a routine provided by the server; and said server being configured to: receive from said client said command; responding to the command by sending the client said first set of data; and if the operation does not modify the LOB, performing the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.

Claim 25

A database system comprising: one or more computer systems coupled to allow communication between processes executing on said one or more computer systems; a client executing on at least one of said one or more computer systems; a server executing on at least one of said one or more computer systems; said client being configured to: send a command that identifies a row in a table to a server, wherein the table includes a LOB column that contains LOBs; receive from the server a first set of data that includes a locator for a LOB that belongs in the LOB column of the row; wherein said locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; and request the server to perform an operation on the LOB by passing the locator for the LOB to a routine provided by the server; and said server being configured to: receive from said client said command; responding to the command by sending the client said first set of data; and if the operation does not modify the LOB, performing the operation on the particular version of the LOB that is identified in the snapshot information contained in the locator passed to the server by the client.

Claim 26

The database system of claim 22 wherein, if the operation modifies the LOB, performing the operation on a most recent version of the LOB.

Claim 27

The database system of claim 22 wherein the server is configured to send the client the first set of data that does not include any LOB data from the LOB that belongs in the LOB column of the row.

Claim 28

The database system of claim 22 wherein the server is configured to send the client the first set of data without the server storing state information that indicates that the client was sent the first set of data.

Claim 29

A database server configured to provide to a client, in response to a command from the client that identifies a row of a table having a large object (LOB) column that contains LOBs, a first set of data that includes a locator for a LOB that belongs in the LOB column of the row, wherein the locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; receive a request from the client to perform an operation on the LOB, wherein the request includes the locator containing the snapshot information that identifies the particular version of the LOB; determine whether the operation will modify the LOB; and if the operation will not modify the LOB, then cause the operation to be performed on the particular version of the LOB that is identified in the snapshot information contained in the locator.

Claim 30

A database server configured to provide to a client, in response to a command from the client that identifies a row of a table having a large object (LOB) column that contains LOBs, a first set of data that includes a locator for a LOB that belongs in the LOB column of the row, wherein the locator includes a LOB identifier that uniquely identifies the LOB and snapshot information that identifies a particular version of the LOB; receive a request from the client to perform an operation on the LOB, wherein the request includes the locator containing the snapshot information that identifies the particular version of the LOB; determine whether the operation will modify the LOB; and if the operation will not modify the LOB, then cause the operation to be performed on the particular version of the LOB that is identified in the snapshot information contained in the locator.

Claim 31

The database server as recited in claim 26 wherein the database server is further configured to if the operation will modify the LOB, then perform the operation on a most recent version of the LOB.

Claim 32

The database server as recited in claim 26, wherein the database server is further configured to provide to the client a first set of data that does not include any LOB data from the LOB that belongs in the LOB column of the row.

Claim 33

The database server as recited in claim 26, wherein the database server is further configured to provide the first set of data to the client without the server storing state information that indicates that the client was sent the first set of data.

Claim 34

The database server as recited in claim 26, wherein the database server is further configured to determine whether the client has permission to perform the operation on the LOB, and store state information that indicates whether the client has permission to perform the operation on the LOB.

Claim 35

The database server as recited in claim 26, wherein: the command from the client specifies a row in a view that includes data from the table, and the database server is further configured provide to the client a locator for the LOB that includes data that identifies the view.

Claim 36

The database server as recited in claim 31, wherein the database server is further configured to determine whether the client has permission to perform the operation by reading from the locator the data that identifies the view and inspecting permissions associated with the view.

Claim 37

The database server as recited in claim 26, wherein the database server is further configured to, before sending said first set of data to the client, if the LOB was selected from a view generate a check value based on one or more values stored in said locator, and store the check value in the locator.

Claim 38

The database server as recited in claim 33, wherein the database server is further configured to, after receiving the locator from the client, if the LOB was selected from a view: read the one or more values and the check value from the locator, determine whether the check value is a valid check value for the one or more values, and perform the operation only if the check value is a valid check value for the one or more values.