liquibase-core/src/main/java/liquibase/Liquibase.java
public void clearCheckSums() throws LiquibaseException {
        LOG.info(LogType.LOG, "Clearing database change log checksums");
        LockService lockService = LockServiceFactory.getInstance().getLockService(database);
        lockService.waitForLock();

        try {
            checkLiquibaseTables(false, null, new Contexts(), new LabelExpression());

            UpdateStatement updateStatement = new UpdateStatement(
                getDatabase().getLiquibaseCatalogName(),
                getDatabase().getLiquibaseSchemaName(),
                getDatabase().getDatabaseChangeLogTableName()
            );
            updateStatement.addNewColumnValue("MD5SUM", null);
            ExecutorService.getInstance().getExecutor(database).execute(updateStatement);
            getDatabase().commit();
        } finally {
            try {
                lockService.releaseLock();
            } catch (LockException e) {
                LOG.severe(LogType.LOG, MSG_COULD_NOT_RELEASE_LOCK, e);
            }
        }
        resetServices();
    }
public void clearCheckSums() throws LiquibaseException {
        LOG.info(LogType.LOG, "Clearing database change log checksums");
        LockService lockService = LockServiceFactory.getInstance().getLockService(database);
        lockService.waitForLock();

        try {
            checkLiquibaseTables(false, null, new Contexts(), new LabelExpression());

            UpdateStatement updateStatement = new UpdateStatement(
                getDatabase().getLiquibaseCatalogName(),
                getDatabase().getLiquibaseSchemaName(),
                getDatabase().getDatabaseChangeLogTableName()
            );
            updateStatement.addNewColumnValue("MD5SUM", null);
            ExecutorService.getInstance().getExecutor(database).execute(updateStatement);
            getDatabase().commit();
        } finally {
            try {
                lockService.releaseLock();
            } catch (LockException e) {
                LOG.severe(LogType.LOG, MSG_COULD_NOT_RELEASE_LOCK, e);
            }
        }
        resetServices();
    }
Sets checksums to null so they will be repopulated next run