Meaning of LFL and XHDR in Db2

I have seen the following messages in Db2diag.log but I do not know what they are. I cannot find any documentation about LFL or XHDR. I know it is related to HADR and log archiving, but what exactly?

2021-07-20-06.26.20.280271-240 E264696A655          LEVEL: Info PID     : 6947266              TID : 5757           PROC : db2sysc 0 INSTANCE: db2inst1             NODE : 000           DB   : SAMPLE HOSTNAME: db2server EDUID   : 5757                 EDUNAME: db2lfr.0 (SAMPLE) 0 FUNCTION: DB2 UDB, recovery manager, sqlplfrFMReadLog, probe:2825 DATA #1 : SQLPLFR_SCAN_ID, PD_TYPE_SQLPLFR_SCAN_ID, 8 bytes LFR Scan Num            = 898596933 LFR Scan Caller's EDUID = 20147 MESSAGE : Reached the max number of retries waiting for the LFL in XHDR. Moving           to next extent. DATA #2 : SQLPG_EXTENT_NUM, PD_TYPE_SQLPG_EXTENT_NUM, 4 bytes 702955 

Do you know one of these terms and where can I get more information?

Meaning of ProductLog

I have the following equation $ $ \frac{2\kappa}{(k+\kappa)^2}=2i\ell e^{-2ik\ell} $ $ with $ \kappa, \ell \in \mathbb{R}$ and $ k\in \mathbb{C}$ which I want to solve for $ k$ .

Using

Reduce[((2*κ)/(k+κ)^2)-2*x*I*Exp[-2*I*l*k]==0, k] 

Mathematica gives me the following solution:

$ (k\neq 0\land l=0\land \kappa =0)\lor \left(l\neq 0\land \kappa =-\frac{i}{l}\land k=0\right)\lor \left(c_1\in \mathbb{Z}\land \sqrt{-i \kappa l e^{-2 i \kappa l}}\neq 0\land l\neq 0\land \kappa +k\neq 0\land \left(k=\frac{-\kappa l+i \cdot\text{ProductLog}\left[c_1,-i \sqrt{-i \kappa l e^{-2 i \kappa l}}\right]}{l}\lor k=\frac{-\kappa l+i \cdot\text{ProductLog}\left[c_1,i \sqrt{-i \kappa l e^{-2 i \kappa l}}\right]}{l}\right)\right)$

I don’t really know how to deal with the ProductLog. I looked it up and know, that ProductLog$ [z]$ gives the principal solution for $ w$ in $ z=we^w$ , which is the Lambert $ W$ function. But what does this actually mean? Is there a way for me to compute without Mathematica, that this is a solution of my equation above?

Or are there maybe any better commands than "Reduce" to find solutions?

Thank you very much for your help!

What is the meaning of invoker level for a Warlock?

Hellfire Warlock prestige class (Fiendish Codex II: Tyrants of the Nine Hells variant, p. 89) mentions:

Invoking: At each level, you gain new invocations known, increased damage with eldritch blast, and an increase in invoker level as if you had also gained a level in the warlock class. You do not, however, gain any other benefit a character of that class would have gained.

What does the book mean by invoker level? The term invoker level is not mentioned in Complete Arcane under Warlock class.

What’s the meaning of “resources external to the SQL Server computer are needed” in Microsoft’s SQL documentation?

In Microsoft’s SQL Server documentation on Windows service account configuration, the decision to use either a VA (virtual account) or a MSA (managed service account) hinges on whether

resources external to the SQL Server computer are needed

What exactly does this phrase mean here? I’m seeking an explanation that makes sense to an ‘accidental DBA’ with minimal experience of SQL Server, or Windows Server, configuration. What counts as a ‘resource’ here, and what kinds of ‘need’ are relevant?

Context: I have a fresh SQL Server 2019 VM on Azure, which was configured with VAs out-of-the-box, and I’m trying to decide whether we need to switch to using MSAs. I have found multiple other questions concerning this same documentation page and/or the same basic decision between VAs or MSAs (or regular AD Accounts) – but none really explain this specific phrase in a way that helps me apply it to my particular scenario. Which is essentially a data warehouse use-case: data will be coming into this SQL instance from external sources, but that’ll be managed by a third-party DW automation application running SSIS scripts, not directly by the SQL engine. (This application has its own AD service accounts.)

Whilst I’ve explained my specific scenario here to try to clarify the question, I’m keen for a generic answer so anyone with any SQL Server use case can evaluate this "resources external to the SQL Server" phrase for their needs. Specific answers for my use case are also welcome.

What’s the meaning of linguistics?

In the programming language theory world, there are two important terminologies, i.e syntax, and semantics.

I can understand these two terminologies:

syntax is about sentence’s structure (e.g. a valid sentence by some grammar)

semantics is about sentence’s meaning (e.g. operational semantics, denotational semantics, etc)

But recently the third word appeared in some PL papers i.e. linguistics, although it is very rare.

What’s the meaning of linguistics?

What’s the relationship between linguistics and syntax/semantics ?

Thanks.

PS: I’m sorry, I don’t know whether it’s suitable to post this question here, because my vision is very narrow…


The following are some PL papers that used this term:

https://users.cs.northwestern.edu/~robby/pubs/papers/aplas2006-fff.pdf

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.23.8118&rep=rep1&type=pdf

Note that this is not a temporary question. The word "linguistic(s)" is not just appeared in these two papers. It also appeared in other papers, but I can’t remember all (sorry). Failure to understand the "linguistic(s)" does not affect the understanding of the paper. I am just curious about the meaning of the "linguistic(s)".

What is the meaning of ‘permanent’ in description of True Polymorph?

Following on from this question: Can I True Polymorph a goblin into adamantine (and then forge him into a sword?)

Casting True Polymorph on an unwilling creature (relevant parts included only):

You transform the creature into a different creature…or into an object.The transformation lasts for the duration, or until the target drops to O hit points or dies. If you concentrate on this spell for the full hour, the transformation becomes permanent. An unwilling creature can make a Wisdom saving throw, and if it succeeds, it isn’t affected by this spell.

Creature into Creature: The target assumes the hit points of its new form, and when it reverts to its normal form, the creature returns to the number of hit points it had before it transformed. If it reverts as a result of dropping to O hit points, any excess damage carries over to its normal form. As long as the excess damage doesn’t reduce the creature’s normal form to O hit points, it isn’t knocked unconscious.

Creature into Object: If you turn a creature into an object, it transforms along with whatever it is wearing and carrying into that form. The creature’s statistics become those of the object, and the creature has no memory of time spent in this form, after the spell ends and it returns to its normal form.

The consensus seems to be that if the creature fails the Wisdom save, you can transform it into a weak creature like a slug or an object like a cup, and can then wait for 61 minutes concentrating on the spell, then stamp on the item and kill it, permanently, because that was its new permanent form. But this seems terribly unbalanced, requiring a single wisdom save to be failed (and these can be influenced with features such as Heightened Spell and Magical Ambush) to kill any creature which can be polymorphed, no matter its stats. This also seems to make True Polymorph a better version of Power Word Kill (if delayed and requiring a save) since it is completely uncapped by health, only by Wisdom save proficiency, as well as including many other functions. This makes it seem unlikely this is the correct interpretation of True Polymorph since it renders another (already weak, for that level) spell almost entirely pointless.

I presumed the spell to be saying that after one hour of concentrating on it, the polymorphed form no longer needs to be concentrated on and could last forever, but will still revert back to the original form if reduced to 0 HP, as described in the linked question where the creature (polymorphed into crafting materials) was cut apart. This seems to make much more sense and retains balance.

Which interpretation is correct? Does the ‘permanent’ section overrule the ‘transforms back if reduced to 0 hit points’ part?

What’s the exact meaning of the phrase “when the target willingly moves” in Booming Blade?

The Booming Blade cantrip’s secondary effect states that “[the target] becomes sheathed in booming energy until the start of your next turn. If the target willingly moves before then, it immediately takes 1d8 thunder damage, and the spell ends”. We can deduce, then:

  • That the damage does not trigger when the target is dragged or pushed around via physical means (grappling, shoving, scenario effects, etc.)
  • That the damage does not trigger when the target is dragged or pushed around via magical means (Gust, Eldritch Blast with Grasp of Hadar, Graviturgist’s Gravity Well, etc.)

This seems pretty clear. However, what happens when the following cases arise?

  • The target is ordered to move via the use of Command (assuming they don’t know yet that the thunderous aura is damaging).
  • The target is forced to move via the use of Compulsion.
  • The target is invited to move via the use of Suggestion.
  • The target is Turned.
  • The target is Frightened and forced to run via Dissonant Whispers.
  • The target has a Geas that prohibits them from ending a turn next to an enemy if they can avoid it.
  • The target is threatened into leaving the area or else. This one seems “willingly”, but are they truly willing if they are panicking because you are telling them you will cut their heads off if they don’t run?

This SageAdvice entry seems to suggest that forcing people to move via mind control spells doesn’t count as willing. However, from what I understand, Jeremy Crawford’s Twitter rulings are no longer considered official, so I was looking for something more solid to make a RAW judgement of this interaction.

Could you explain the meaning of warlock invocation number next to its grade?

I am rolling a warlock in my current campaign and we started at level 3. For my invocations, I have picked walk unseen and fell flight. I was told I could not do that by my DM since he told me my level wasn’t enough. However, when I referred back to my Complete Arcane, it mentioned:

A least invocation has a level equivalent of 1st or 2nd; a lesser, 3rd or 4th; a greater, 5th or 6th; and a dark invocation has a level equivalent of 6th or higher (maximum 9th).

So I automatically assumed that at level 1 and 2, I have access to least and 3 and 4, I have access to lesser, turns out not.

When I refered back to Complete Arcane for the invocations I picked, it said:

Fell Flight: Lesser; 3rd

and

Walk Unseen: Lesser; 2nd

I am really confused about which level can I pick these two invocations? I would appreciate it if you could explain how the warlock level corresponds to the invocation grade and the number next to it.