introduction to oracle9i sql solutions

... have ever attended, to excite them to learn, and to make them want to come back for more • To give you some tips and techniques to help you vary your lecture style, avoid monotony in classes, and ... the capabilities that SQL lacks and how PL/SQL serves as an extension to SQL The objective of this slide is to highlight that PL/SQL combines the data manipulating power of SQL with the data processing ... operator.htm#998054 Using the AND Operator AND requires both conditions to be TRUE. SQL> SELECT empno, ename, job, sal Using the OR Operator OR requires either condition to be TRUE. SQL>

Ngày tải lên: 24/01/2014, 10:20

... Management Tool s and AWS Mi grati on Competenci es Trang 3Eric WrightIntroduction to AWS IaaS Solutions Deploying and Managing Amazon Web Services Boston Farnham Sebastopol Tokyo Beijing Boston Farnham ... 7Welcome to the Introduction to AWS IaaS solutions guide The goal of this guide is to introduce systems administrators, systems archi‐tects, and newcomers to Amazon Web Services (AWS) to some ... 9CHAPTER 1Introduction to AWS Today’s systems administrators need to acquire and strengthen theirskills on public cloud platforms Amazon Web Services (AWS)began as an infrastructure to run the

Ngày tải lên: 12/11/2019, 22:22

... Grinstead and J Laurie Snell:INTRODUCTION to PROBABILITYPublished by AMS Solutions to the exercises SECTION 1.1 1 As n increases, the proportion of heads gets closer to 1/2, but the difference ... P (male lives to age x) = number of male survivors at age x Trang 3Qx= P (female lives to age x) = number of female survivors at age x29 (Solution by Richard Beigel) (a) In order to emerge from ... male living to 80 is 41, and for a female it is 62 33 You have to make a lot of calculations, all of which are like this: W, LLW, LLLLW, The probability that this happens is equal to p + q2p

Ngày tải lên: 05/06/2014, 11:31

... unordered, left to right 3 Tuples are unordered, top to bottom 4 There are no duplicate tuples Now justify them: 1 Regarding normalization: You should be aware that the history here is somewhat ... reference to Chapter 9 6.6 SQL Facilities SQL supports rows, not tuples (remind students of [some of] the differences) Briefly explain columns, fields, row value constructors, row type constructors, ... (at least in SQL) are allowed to include nulls (forward reference to Chapter 19); and (c) the horrible but widespread perception that "relations are flat" (forward reference to Chapter

Ngày tải lên: 06/08/2014, 01:21

... aggregate operators COUNT, SUM, etc., are first mentioned Observe the important differences (both syntactic and semantic) in the treatment of such operators between Tutorial D and SQL Note too the ... SP WHERE P# = 'P2' ) ; In a sense, this SQL expression corresponds more directly to the semijoin formulation than to the join one Analogous remarks apply to semidifference Trang 4Regarding extend: ... input to the join, meaning there's less data to be scanned to do the join, and the result of the join is smaller as well In fact, the second expression might allow the result of the join to be

Ngày tải lên: 06/08/2014, 01:21

... TEACHER to OFFERING, ENROLLMENT to OFFERING, and OFFERING to COURSE are all properly maintained, the referential constraints from TEACHER to COURSE and ENROLLMENT to COURSE will be maintained automatically ... update operation must ever assign to any relvar a value that causes its relvar predicate to evaluate to FALSE The text doesn't say this explicitly, but the rule applies to all relvars, derived as well ... they're not the recommended solution 9.12 SQL Facilities Mostly self-explanatory but note that "self-explanatory" is not the same thing as making sense Answers to Exercises 9.1 INSERT on S, UPDATE

Ngày tải lên: 06/08/2014, 01:21

... self-explanatory (though project is a little trickier than the operators covered prior to this point) Note: The subsection says: "An attempt to update the SC tuple (S1,London) to (S2,London) ... applies to INSERT: a Inserting the tuple (s,sn,st,sc,rt) into the join is equivalent to inserting the tuple (s,sn,st,sc) into S (unless it's already present) and inserting the tuple (s,rt) into ... ubiquitous that the unqualified term view has come to mean, almost always, a "materialized view" specifically! And so we no longer have a good term to use when we want to refer to a view

Ngày tải lên: 06/08/2014, 01:21

... probably just be skimmed if the instructor doesn't want to get too deeply into formal proofs and the like Indeed, the chapter is included, in part, just to show that there really is some mathematical ... specifically The "right" way to do database design is to do a clean logical design first, and then, as a separate and subsequent step, to map that logical design into whatever physical structures ... the FD notion might have a role to play in logical database Trang 6design──we'll be wanting to get rid of redundancy and therefore we'll be wanting to find ways to get rid of certain FDs) • Some

Ngày tải lên: 06/08/2014, 01:21

... possible to "spot" a BCNF decomposition──only that it's often possible to do so in practical cases To revert to the company database example: As a subsidiary exercise──not much to do with ... candidate key, together with an attribute for every box pointed to from the original box (and no other attributes) Of course, some refinement is needed to this loose statement in order to take care ... of the exercise and those corresponding to reasonable semantic assumptions (stated explicitly below) The attribute names are intended to be self-explanatory ╔════════════════════════════════════════════════════════════════╗

Ngày tải lên: 06/08/2014, 01:21

... in DK/NF, then R is automatically in 5NF (and hence 4NF, BCNF, etc.) as well However, it's wrong to think of DK/NF as another step in the progression from 1NF to 2NF to to 5NF, because 5NF is ... is straightforward──all that's necessary is to replace the references to FDs and BCNF by analogous references to MVDs and 4NF, thus: 1 Initialize D to contain just R 2 For each non4NF relvar ... introductory paragraph) of the text──slightly edited here──of a message posted on the website www.dbdebunk.com in May 2003 It's my response to a question from someone I'll refer to here as Victor

Ngày tải lên: 06/08/2014, 01:21

... ; EXEC SQL START TRANSACTION ; EXEC SQL OPEN CP ; DO WHILE ( NOT eof ) ; DO count := 1 TO 10 ; EXEC SQL FETCH CP INTO :P#, ; IF SQLSTATE = '02000' THEN DO ; EXEC SQL CLOSE CP ; EXEC SQL COMMIT ... of, e.g., two people both trying to use the bathroom at the same time in the morning The solution to the problem is to introduce a mechanism (door locks) and a protocol for using that mechanism ... Self-explanatory 16.5 Deadlock Mostly self-explanatory Explain the Wait-For Graph (it isn't discussed in detail in the text because it's fairly obvious, not to say trivial; see the answer to Exercise

Ngày tải lên: 06/08/2014, 01:21

... question Could perhaps sidetrack to review the origins of SQL here, and the current ironical situation, if the instructor is familiar with this story and wants to discuss it (see reference [4.16]) ... section mentions the fact that 3VL, SQL's (flawed) support for 3VL, and duplicate rows all serve as optimization inhibitors (and the same is true for SQL's left-to-right column ordering, though ... selection (using indexes and other storage structures appropriately to get to the stored data) The relational model is directly relevant to the first aspect, inasmuch as it's the formal properties of

Ngày tải lên: 06/08/2014, 01:21

... representation, together with a corresponding selector operator and a corresponding set of THE_ operators (or logical equivalents of same) ■ "=" and ":=" operators ■ Certain type ... operators that applied to values of type A would be a subset of the set of operators that applied to values of type B and vice versa (and, of course, the set of constraints that applied to values ... read-only vs update operator distinctions come into play Other approaches don't make these distinctions; they thus allow operators (update as well as read-only operators) to be inherited indiscriminately──with

Ngày tải lên: 06/08/2014, 01:21

... tends to be driven by physical considerations much more than by logical ones──indeed, it tends to blur the logical vs physical distinction considerably." Caveat lector We use SQL, not Tutorial ... always implies data aggregation, usually according to many different groupings In classical relational languages (and in SQL too, prior to SQL:1999), each individual query involves at most one ... in certain SQL implementations and also (since SQL:1999) in the SQL standard as well Bundling several queries into one statement might be a good idea, but bundling the results into one table

Ngày tải lên: 06/08/2014, 01:21

... whether the FROM-TO intervals in the previous version of the database are to be interpreted as closed or open with respect to FROM and TO Previously, those intervals were implicitly taken to be closed ... problem of having to make an arbitrary choice as to which of two candidate keys should be regarded as primary For example, relvar S_FROM_TO had two candidate keys, {S#,FROM} and {S#,TO}, but relvar ... constraints to guard against the absurdity of a FROM-TO pair appearing in which the TO value is less than the FROM value are no longer necessary, because the constraint "FROM ≤ TO" is

Ngày tải lên: 06/08/2014, 01:21

... "constructor" we need is an operator that creates a relvar (e.g., CREATE TABLE, in SQL terms) Selectors, by contrast, select values Also, of course, constructors return pointers to the constructed ... though I would prefer to use the more conventional term operators.* Bundling methods with classes is not essential, however, and leads to several problems [3.3]; I would prefer to define "classes" ... in two different senses: Sometimes it seems to mean the operator as seen by the user, sometimes it seems to mean the code that implements that operator Yet another example of confusing model and

Ngày tải lên: 06/08/2014, 01:21

... Point out that (to quote) "the XML document isn't a very faithful representation of a parts relation, because it imposes a top-to-bottom sequence on the tuples and a left-to-right sequence ... these is very unclear to me, since (as we saw in the previous section) XML collection support has nothing to do with the DBMS, and SQL is supposed to a standard that relates to DBMSs (meaning functionality ... the user to navigate to the others • The World Wide Web is the agggregate of information stored on the Internet, together with the associated Web standards for interfaces and protocols by

Ngày tải lên: 06/08/2014, 01:21

... operator (see Chapter 5), and the whole idea of being able to invoke it from inside a read-only operation (SELECT in SQL) is more than a little suspect [3.3] • Consider the expression XMLFILETOCLOB ... XMLFILETOCLOB function is more than a little reminiscent of the EXECUTE IMMEDIATE operation of dynamic SQL (see Chapter 4) • Remarks analogous to those in the previous paragraph apply also to arguments ... ability for users to define their own types; they therefore don't force users to represent everything in character-string form, and indeed they provide very strong incentives not to Second, there's

Ngày tải lên: 06/08/2014, 01:21

... used to supplement declarative referential integrity, to enforce complex business rules, or to audit changes to data. The code within a trigger, called the trigger body, is made up of PL/SQL blocks ... to audit changes to data in the BOOKSHELF table, then you may insert a record into a different table (say, BOOKSHELF_AUDIT) every time a record is changed in BOOKSHELF. To do this, you need to ... to insert into BOOKSHELF_AUDIT (to perform the triggered transaction). NOTE The privileges needed for triggered transactions cannot come from roles; they must be granted directly to the creator

Ngày tải lên: 07/08/2014, 14:20

... etc I SQLite - use SQL without a database server I PROC SQL in SAS Trang 30SQL Ways to Use SQLI console command (mysql -u user -p dbname) I GUI interfaces are often available I Interfaces to many ... etc I SQLite - use SQL without a database server I PROC SQL in SAS Trang 28Introduction toI console command (mysql -u user -p dbname) I GUI interfaces are often available I Interfaces to many ... etc I SQLite - use SQL without a database server I PROC SQL in SAS Trang 29Introduction toI console command (mysql -u user -p dbname) I GUI interfaces are often available I Interfaces to many

Ngày tải lên: 22/10/2014, 16:47