If a transaction starts before backup start time and transaction commi

1.	If a transaction starts before backup start time and transaction committed before the completion of the full backup. Please explain which data would be included in the full backup.
Answer» DCM (Differential CHANGED map): DCM is used by SQL server for differential backup. DCM pages keep TRACK of all extents which has changed since the last full database backup. During SQL server differential backup, database ENGINE reads the DCM page and takes a backup of only those pages which has been changed since the last full backup. If the value is 1 means extent has been modified and 0 means not modified. After each full backup, all these extents are marked to 0. BCM (Bulk Changed map): BCM page is used in bulk-logged recovery model to track EXTENDS changed DUE to bulk-logged or minimally logged operations. During log backup, the database engine reads BCM page and includes all the extents which have been modified by the bulk-logged process. If the Value 1 means modified extent and 0 means not modified. After each log backup, all these extents are marked to 0

If a transaction starts before backup start time and transaction committed before the completion of the full backup. Please explain which data would be included in the full backup.

Answer»

DCM (Differential CHANGED map): DCM is used by SQL server for differential backup. DCM pages keep TRACK of all extents which has changed since the last full database backup.

During SQL server differential backup, database ENGINE reads the DCM page and takes a backup of only those pages which has been changed since the last full backup. If the value is 1 means extent has been modified and 0 means not modified. After each full backup, all these extents are marked to 0.

BCM (Bulk Changed map): BCM page is used in bulk-logged recovery model to track EXTENDS changed DUE to bulk-logged or minimally logged operations.

During log backup, the database engine reads BCM page and includes all the extents which have been modified by the bulk-logged process. If the Value 1 means modified extent and 0 means not modified. After each log backup, all these extents are marked to 0

If a transaction starts before backup start time and transaction committed before the completion of the full backup. Please explain which data would be included in the full backup.

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