System and method for improving data recovery performance

Claim 2

In a computerized database system having a central processing unit (CPU), volatile memory, non-volatile memory, a plurality of data stored in at least one database, wherein a plurality of transactions access a database for reading or updating, and for each database access, a transaction record is stored at an offset location in a sequential log, a method for recovering a database, comprising the steps of: during transaction processing of a database, tracking at least one log range comprising update transaction log records, said log range having a begin value and an end value, said begin value corresponding to a log offset location of a first access of the database only by an updating transaction and said end value corresponding to a log offset location at a commit or abort only of a last updating transaction; and during recovery of the database, applying the update transaction log records in said log range to a version of the database stored in non-volatile memory.

Claim 3

The method of claim 1, further comprising the steps for tracking the log range of: a) designating each database as a pseudo close database; b) tracking when an updating transaction accesses a database; c) for a pseudo close database accessed by an updating transaction, designating the pseudo close database as a pseudo open database and recording a corresponding offset location as the log range begin value; d) for a pseudo open database not accessed by an updating transaction for a predetermined period, designating the pseudo open database as pseudo close and recording a corresponding offset location as the log range end value; and e) repeating steps (b) through (d) a plurality of times.

Claim 4

The method of claim 2 wherein the predetermined period is based on time.

Claim 5

The method of claim 2 wherein the predetermined period is based on the number of records in the log.

Claim 6

The method of claim 2 further comprising the steps for tracking when an updating transaction accesses a pseudo open database of: maintaining a counter of uncommitted transactions updating a database; incrementing the counter when an updating transaction accesses the database; and decrementing the counter when the updating transaction is committed or aborted, wherein when the counter has a value of zero, there are no updating transactions accessing the database.

Claim 7

In a computerized database system having a central processing unit (CPU), volatile memory, non-volatile memory, and a plurality of data stored in a plurality of databases, wherein a plurality of transactions access a database for reading or updating, wherein for each database access, a transaction record is stored at an offset location in a sequential log, a method for recovering a database, comprising the steps of: during transaction processing of a database: a) designating each database as a pseudo close database; b) tracking when an updating transaction accesses a database; c) for a pseudo close database accessed by an updating transaction, designating the pseudo close database as a pseudo open database and recording a corresponding offset location of the sequential log as a log range begin value; d) maintaining a counter of uncommitted transactions updating a pseudo open database; e) incrementing the counter when an updating transaction accesses the pseudo open database; f) decrementing the counter when the updating transaction is committed or aborted, wherein when the counter has a value of zero, there are no updating transactions accessing the database; g) for a pseudo open database not accessed by an updating transaction for a predetermined period, designating the pseudo open database as a pseudo close database and recording a corresponding offset location of the sequential log as a log range end value; and h) repeating steps (d) through (g) a plurality of times; during recovery of the database: applying update transaction log records between each log range begin value and log range end value to a version of the database stored in non-volatile memory.

Claim 8

In a computerized database system having a central processing unit (CPU), volatile memory, non-volatile memory, and a plurality of data stored in a plurality of databases, wherein a plurality of transactions access a database for reading or updating, wherein for each database access, a transaction record is stored at an offset location in a sequential log, a method for recovering a database, comprising the steps of: during transaction processing of a database: a) designating each database as a pseudo close database; b) tracking when an updating transaction accesses a database; c) for a pseudo close database accessed by an updating transaction, designating the pseudo close database as a pseudo open database and recording a corresponding offset location of the sequential log as a log range begin value; d) maintaining a counter of uncommitted transactions updating a pseudo open database; e) incrementing the counter when an updating transaction accesses the pseudo open database; f) decrementing the counter when the updating transaction is committed or aborted, wherein when the counter has a value of zero, there are no updating transactions accessing the database; g) for a pseudo open database not accessed by an updating transaction for a predetermined period, designating the pseudo open database as a pseudo close database and recording a corresponding offset location of the sequential log as a log range end value; and h) repeating steps (d) through (g) a plurality of times; during recovery of the database: applying update transaction log records between each log range begin value and log range end value to a version of the database stored in non-volatile memory.

Claim 9

A computerized system for recovering a database wherein a plurality of transactions access the database for reading or updating, and for each database access, a transaction record is stored at an offset location in a sequential log, said system comprising: means for designating the database as a pseudo close database; means for tracking when an updating transaction accesses a database; means for designating a pseudo close database accessed by an updating transaction as a pseudo open database; means for recording an open log location only when an updating transaction first accesses a pseudo close database as a log range begin value; means for designating a pseudo open database not accessed by an updating transaction for a predetermined period as a pseudo close database; means for recording a close log location only when a last updating transaction commits or aborts as a log range end value; and means for applying update transaction log records in between said log range begin value and said log range end value to a version of the database stored in non-volatile memory.

Claim 10

A computerized system for recovering a database wherein a plurality of transactions access the database for reading or updating, and for each database access, a transaction record is stored at an offset location in a sequential log, said system comprising: means for designating the database as a pseudo close database; means for tracking when an updating transaction accesses a database; means for designating a pseudo close database accessed by an updating transaction as a pseudo open database; means for recording an open log location only when an updating transaction first accesses a pseudo close database as a log range begin value; means for designating a pseudo open database not accessed by an updating transaction for a predetermined period as a pseudo close database; means for recording a close log location only when a last updating transaction commits or aborts as a log range end value; and means for applying update transaction log records in between said log range begin value and said log range end value to a version of the database stored in non-volatile memory.

Claim 11

The system of claim 7 further comprising: means for maintaining a counter of uncommitted transactions updating a database; means for incrementing the counter when an updating transaction accesses the database; and means for decrementing the counter when an updating transaction has been committed or aborted, wherein when the counter has a value of zero, there are no updating transactions accessing the database.