temporal-tables

问题 Tom Kyte describes temporal tables here: temporal tables are tables that can return the answer that existed at a point in time -- you can ask the table to return the answer that existed at midnight last night, instead of the answer that exists right now Do such tables exist in Oracle? I can't find documentation of them. How can I create one and use it? He says they exist in databases, although he doesn't say that they do in Oracle nor any other product. Is this a conceptual thing not

问题 When temporal table is created, we need to defined start and end date time columns which can be hidden - not visible in SELECT * or INSERT without columns . I want to add one more column, which will contain information about the user who has commit the change. The issue is, I am getting the following error: Msg 13735, Level 16, State 1, Line 10 Cannot alter HIDDEN attribute on column 'UserID' in table 'GK' because this column is not a generated always column. Here is the code: DROP TABLE IF

问题 When temporal table is created, we need to defined start and end date time columns which can be hidden - not visible in SELECT * or INSERT without columns . I want to add one more column, which will contain information about the user who has commit the change. The issue is, I am getting the following error: Msg 13735, Level 16, State 1, Line 10 Cannot alter HIDDEN attribute on column 'UserID' in table 'GK' because this column is not a generated always column. Here is the code: DROP TABLE IF

问题 I have created temporal tables based on Microsoft SQL Docs Creating a temporal table with a default history table . https://docs.microsoft.com/en-us/sql/relational-databases/tables/creating-a-system-versioned-temporal-table?view=sql-server-ver15#creating-a-temporal-table-with-a-default-history-table Migration: public partial class Temporaltables : Migration { List<string> tablesToUpdate = new List<string> { "Images", "Languages", "Questions", "Texts", "Medias", }; protected override void Up

问题 We are using EF Core and SQL Server 2016 for our .NET Core Web API. I am evaluating use of temporal tables and its impact on EF Core code. When I generate the EF model using cmdline then it generates model with appstart, append and mappings in dbcontext . When I do insert/update they fail saying these columns cannot be updated. I had to remove appstart, end from model and dbcontext mapping to make it work. I read there is no interception capability yet in EF Core like EF 6.x. Please advise

问题 We have JCC feed that pumping data from Oracle to SQL Server 2016 . For some unknown reasons there are duplicates in the history table with THE SAME start and end times. How can it happen? I tried to update record with the condition SET Column = Column . In that case I have 2 records where all the fields are the same, but start and end times are different. How can it happen that there are same datetimes? UPDATE : DDL: CREATE TABLE [dbo].[LEASES]( [LEASE_NUMBER] [CHAR](7) NOT NULL, [CREDIT

问题 are there any information in the net, where i can verify how hight are the storage costs for temporal tables feature? Will the server creates a the full hardcopy of the row/tuple that was modified? Or will the server use a reference/links to the original values of the master table that are not modified? For example. I have a row with 10 columns = storage 100 KB. I change one value of that row, thow times. I have thow rows in the historical table after that changes. Is the fill storage cost

问题 I am trying to implement basic support for SQL Server 2016 temporal tables in NHibernate 4.x. The idea is to alter SQL statement from SELECT * FROM Table t0 to SELECT * FROM Table FOR SYSTEM_TIME AS OF '2018-01-16 00:00:00' t0 You can find more info about temporal tables in SQL Server 2016 here Unfortunately, I've not found any way to insert FOR FOR SYSTEM_TIME AS OF '...' statement between table name and its alias. I'm not sure if custom dialects supports this. The only working solution I

问题 I have implemented a system versioned (temporal) table on one of our production tables that is frequently updated. This table is updated by applications, power users (manually with custom scripts and standardized sprocs), and system jobs. I have just run into a situation where I see a new record inserted into the history table but it appears exactly the same as the one before it. As I research this I see it is not a one off situation; there are many more. Please keep in mind the begin and end

问题 I have a temporal table Employee with EmployeeHistory as its history table. In C#, I am using SqlConnection to query the data from SQL Server for the entire history of an employee. var data = Conn.ExecuteReader("select * from Employee e FOR SYSTEM_TIME ALL WHERE e.Id=15"); This throws the error: Incorrect syntax near FOR So, how do we query history data for a temporal table in C# using SqlConnection ? 回答1: Problem is you are using table alias e and so the error. Don't think you can use table