-- 为导出分片任务补充 offset/limit 分片字段
ALTER TABLE tb_export_shard_task
    ADD COLUMN IF NOT EXISTS shard_offset BIGINT NOT NULL DEFAULT 0,
    ADD COLUMN IF NOT EXISTS shard_limit INT NOT NULL DEFAULT 0;

COMMENT ON COLUMN tb_export_shard_task.shard_offset IS '分片偏移量(offset)';
COMMENT ON COLUMN tb_export_shard_task.shard_limit IS '分片行数上限(limit)';
