The memory structure which is a flashback boss & so starts the process that will actually do it then we will cover come flashback works and you much greater detail later on so for now when you do the exercise please just do it alter the database for slogging well let’s just see how much more aware of here if I may create a table I’ll just also use a chop o clock identified by Tiger right Scott tiger ok questions if I do this Craig table t1 and select star from employ logging deed that statement generate redo it spans the GF force blogging turned on I don’t think it does create redo adjustable propagator the standby that’s a look forceful in to come back so Jeremy fence like for folding over your database oops Oh TJ’s to Ascot DA thanks to screw off I don’t normally do this on all my production systems horse logging is not enabled and you’re actually not correct Chris that will not subject redo that will not have generated redo oh sorry it will generation to redo.
It will have generated redo because I didn’t do a direct load let’s just check test author approaches oh that’s all for trace on snap Craig variable T to a select star from amp no logging off do they also show up to the detail section up no mistake a bit differently I’ll truncate ask you a different question and then we’ll see through truncate table t2 right if I insert into T to select star from em that generates 2.6 kilobytes we do ok call back if I then insert select star from imp can’t put any logging on the end any login that generation 1 kilobyte to redo, so the video is much less but all like so let’s make sure I get consistent paid yeah let’s now do that like at the same thing that was double the redo because of the bill necessary for the first time I remit to allocate space but you can see there’s no difference for the pending their logging or not are all that back you’ll seek the no logging statement run this again 1k of redo roll all back then I wrong for a no login keyword.
One can every do even though I thought that this most of immediate relevance just remember if almost in is very difficult to stop Oracle from generation redo if I do it like this insert faster tougher penned so fast I can even more do it’s almost impossible to stop oracle generation reading rollback even with the direct load it’s very health support generation we do know what to do and what will stop though it’s things like creating indexes with the moat locking keyword direct load if it’s a big enough Tara load you will not get redo it has to be direct load and the no logging keyword and then the changes will not be written out to the redo log where generation redo but discarding it is what it comes down to its generators and discarded it will normally behave, so the problem comes though with things like index generation if I kind of index cred index I one bond for I to on p2p name I can do that with no logging and that will not generate redo that’s going to destroy the discard environment.
So you must have for slogging on also further base forced blogging so to summarize that it’s actually very difficult to stop Oracle generation redo, but that did not generate Idea you must enable for slogging because otherwise but index won’t exist in the remote database and you give them a repulsion idea or a must database exactly what will happen is change vectors will be sent across later on but apply to the non-existent index and then you’re going to get all sorts of business some are errors so always able for slogging now log files all right my redo log select star from lee de la frog scratch that window and also trace off back up Vesta oh man type I creation, so that’s it I did eventually finally do it so they nice then 300 select star from trees on the Lord when you see me making stupid mistakes has bed smelling, so there’s the online lock I’ve got three groups they are multiplexed and they’re 50 megabytes each.
Now I said before there’s no change in the way we generate redo and what we do need to do though it’s quite what we call standby log files what type of log files of these little look tells me that remember to change a change and then select star from Vigor log file Becca do so and they’re the members that make a further search going forward action now then you go online looks I need now to create what we call standby logs theoretically you don’t need to do this practical purposes you always do so same thanks now I am using oracle manage files okay organize files people tell me to do you an always try to use or commands files be never use or pronounce files thin of a mixture be done’t know what they seed fish are you an Oracle nominalism yeah we use the Sm 0 this was a yep okay bear with me here to the dish if you’re using for you Krista figure I would always use oracle bones files if you possibly can parameters share parameter.
Create these parameters here oracle manage files introduced in early snowing and back in released nine I thought I’ll never use that completely sit down the line how did I live without it I use all commands files all the time and if these parameters here so if you set just the one that’s a default location for the entire database it’s sex for multiplex copies of online law can control the entire database except for the multiplex copies which goes to the afar a nice the entire database goes where if you want them you can set these and that means your data files will go there then your online logs we’re going to whatever destinations you say here so if you’re if you want two copies of each online log group you’ll set two of these an inch group of a membrane inch one so if you’re using Oracle manage files I can create my standby look past just like this also database pad standby and stand by log file using Oracle manage files complete automation I can just do that nice.
If you’re not using Oracle manage files you have to do a lot more work you’ll bead and then you’ll have to give it the case that names the file nice what if I go up now well if we look at Vida log there’s no change but if I look Vida Luke fanboy log I’ve now got a stand by local groups number for which thing size 100 megabytes wife actually not going to be any good and we’ll see why in a second don’t they have been hidden eyes are your primary exactly that’s why doing completely on these force is not going to work right so well do is drop it alter database drop standby log file groups for so even if you’re using or Comanche files you will want to specify a size five in my case I think that’s 50 megabytes in this size 50 megabytes right let’s see what we’ve got now yes that’s the correct size now sharing we’re saying they need to be the same sign.
If they aren’t the same size they won’t be used as a personal yep but has a lot of knock-on effect that will see later on we are and that you will believe it once yeah well it happens typically is this um you don’t get real-time apply the redo get sent over as an archive log Oracle well you should have one more standby log file the number of redo logs I never quite understood why that is the case then logic there so I’ll just do it I’ve got three online looks so I’ll add a total of four standby locks it’s the launch it behind us is that is to do with as you all know oh no I lost you I’m in archive log mount okay I’ve got three locks on drugs my current one is Group on the older ones have been archived now anything goes wrong with our climbing and can’t archive the database in contrast all right at the spam beliefs on standby launch have to be archived and if they can’t be archived.