romikgosai/squad_modified huggingface dataset:
The 1980s ushered in the age of desktop computing. The new computers empowered their users with spreadsheets like Lotus 1-2-3 and database software like dBASE. The dBASE product was lightweight and easy for any computer user to understand out of the box. C. Wayne Ratliff the creator of dBASE stated: "dBASE was different from programs like BASIC, C, FORTRAN, and COBOL in that a lot of the dirty work had already been done. The data manipulation is done by dBASE instead of by the user, so the user can concentrate on what he is doing, rather than having to mess with the dirty details of opening, reading, and closing files, and managing space allocation." dBASE was one of the top selling software titles in the 1980s and early 1990s.

Questions and answers:
['
Q: Who created dBASE?
A: C. Wayne Ratliff', '
Q: Why was dBASE unique?
A: data manipulation is done by dBASE', '
Q: Why was dBASE successful?
A: lightweight and easy for any computer user to understand out of the box', '
Q: What is a benefit of using dBASE?
A: managing space allocation']
The 1990s, along with a rise in object-oriented programming, saw a growth in how data in various databases were handled. Programmers and designers began to treat the data in their databases as objects. That is to say that if a person's data were in a database, that person's attributes, such as their address, phone number, and age, were now considered to belong to that person instead of being extraneous data. This allows for relations between data to be relations to objects and their attributes and not to individual fields. The term "object-relational impedance mismatch" described the inconvenience of translating between programmed objects and database tables. Object databases and object-relational databases attempt to solve this problem by providing an object-oriented language (sometimes as extensions to SQL) that programmers can use as alternative to purely relational SQL. On the programming side, libraries known as object-relational mappings (ORMs) attempt to solve the same problem.

Questions and answers:
['
Q: In the 1990s, what type of programming changed the handling of databases?
A: object-oriented', '
Q: What term is used for the difficulty in database table and programmed object translation?
A: object-relational impedance mismatch', '
Q: How is the problem of object-relational impedance mismatch corrected?
A: object-oriented language', '
Q: What is the library programmers use to solve object-relational impedance mismatch?
A: object-relational mappings (ORMs)']
XML databases are a type of structured document-oriented database that allows querying based on XML document attributes. XML databases are mostly used in enterprise database management, where XML is being used as the machine-to-machine data interoperability standard. XML database management systems include commercial software MarkLogic and Oracle Berkeley DB XML, and a free use software Clusterpoint Distributed XML/JSON Database. All are enterprise software database platforms and support industry standard ACID-compliant transaction processing with strong database consistency characteristics and high level of database security.

Questions and answers:
['
Q: What kind of database is XML?
A: structured document-oriented database', '
Q: Where are XML databases frequently used?
A: enterprise database management', '
Q: What type of processing is used in enterprise database software?
A: ACID-compliant transaction processing', '
Q: How is XML used in enterprise database management?
A: machine-to-machine data']
In recent years there was a high demand for massively distributed databases with high partition tolerance but according to the CAP theorem it is impossible for a distributed system to simultaneously provide consistency, availability and partition tolerance guarantees. A distributed system can satisfy any two of these guarantees at the same time, but not all three. For that reason many NoSQL databases are using what is called eventual consistency to provide both availability and partition tolerance guarantees with a reduced level of data consistency.

Questions and answers:
['
Q: What is used to offer a balance in guarantees?
A: eventual consistency', '
Q: What explains the difficulty in a system containing availability, consistency, and partition tolerance guarantees?
A: the CAP theorem', '
Q: How many guarantees will most databases tolerate?
A: two']
The first task of a database designer is to produce a conceptual data model that reflects the structure of the information to be held in the database. A common approach to this is to develop an entity-relationship model, often with the aid of drawing tools. Another popular approach is the Unified Modeling Language. A successful data model will accurately reflect the possible state of the external world being modeled: for example, if people can have more than one phone number, it will allow this information to be captured. Designing a good conceptual data model requires a good understanding of the application domain; it typically involves asking deep questions about the things of interest to an organisation, like "can a customer also be a supplier?", or "if a product is sold with two different forms of packaging, are those the same product or different products?", or "if a plane flies from New York to Dubai via Frankfurt, is that one flight or two (or maybe even three)?". The answers to these questions establish definitions of the terminology used for entities (customers, products, flights, flight segments) and their relationships and attributes.

Questions and answers:
['
Q: What should a conceptual data model do?
A: reflects the structure of the information to be held', '
Q: What makes a successful data model?
A: accurately reflect the possible state of the external world being modeled', "
Q: Asking questions about an organization's needs will help to create what?
A: definitions of the terminology used for entities", '
Q: What must one understand in order to create a successful data model?
A: the application domain']
Having produced a conceptual data model that users are happy with, the next stage is to translate this into a schema that implements the relevant data structures within the database. This process is often called logical database design, and the output is a logical data model expressed in the form of a schema. Whereas the conceptual data model is (in theory at least) independent of the choice of database technology, the logical data model will be expressed in terms of a particular database model supported by the chosen DBMS. (The terms data model and database model are often used interchangeably, but in this article we use data model for the design of a specific database, and database model for the modelling notation used to express that design.)

Questions and answers:
['
Q: A conceptual data model in separate from the choice of what?
A: database technology', '
Q: In what form is the output of a logical database design?
A: schema', '
Q: Which data model is displayed as a specific model that uses DBMS?
A: logical']
The final stage of database design is to make the decisions that affect performance, scalability, recovery, security, and the like. This is often called physical database design. A key goal during this stage is data independence, meaning that the decisions made for performance optimization purposes should be invisible to end-users and applications. Physical design is driven mainly by performance requirements, and requires a good knowledge of the expected workload and access patterns, and a deep understanding of the features offered by the chosen DBMS.

Questions and answers:
['
Q: What decisions must be made in the last stage of database design?
A: performance, scalability, recovery, security', '
Q: What is an important goal in in this final stage?
A: data independence', '
Q: What factor is reflected in performance requirements?
A: Physical design']
While there is typically only one conceptual (or logical) and physical (or internal) view of the data, there can be any number of different external views. This allows users to see database information in a more business-related way rather than from a technical, processing viewpoint. For example, a financial department of a company needs the payment details of all employees as part of the company's expenses, but does not need details about employees that are the interest of the human resources department. Thus different departments need different views of the company's database.

Questions and answers:
['
Q: How many conceptual or physical views of data are there?
A: one', '
Q: How many different external views of data are there?
A: any number', '
Q: What is the benefit of external views of data?
A: see database information in a more business-related way']
The conceptual view provides a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it abstracts away details of how the data are stored or managed (internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels (e.g., relational model). The internal level, which is hidden inside the DBMS and depends on its implementation, requires a different level of detail and uses its own types of data structure types.

Questions and answers:
['
Q: What does the conceptual view offer?
A: a level of indirection between internal and external', '
Q: How does the conceptual view handle how data is managed?
A: abstracts away details', '
Q: What type of view does the conceptual view offer?
A: common']
Database storage is the container of the physical materialization of a database. It comprises the internal (physical) level in the database architecture. It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the conceptual level and external level from the internal level when needed. Putting data into permanent storage is generally the responsibility of the database engine a.k.a. "storage engine". Though typically accessed by a DBMS through the underlying operating system (and often utilizing the operating systems' file systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage (e.g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize (the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data (e.g., when querying the database).

Questions and answers:
['
Q: What is responsible for putting information into permanent storage?
A: database engine', '
Q: What do database administrators closely monitor?
A: storage properties and configuration setting', '
Q: What is database storage?
A: physical materialization of a database', '
Q: While working, does DBMS store information in one place?
A: several types of storage', '
Q: What are huge quantities of information stored as?
A: bits']
Database access control deals with controlling who (a person or a certain computer program) is allowed to access what information in the database. The information may comprise specific database objects (e.g., record types, specific records, data structures), certain computations over certain objects (e.g., query types, or specific queries), or utilizing specific access paths to the former (e.g., using specific indexes or other data structures to access information). Database access controls are set by special authorized (by the database owner) personnel that uses dedicated protected security DBMS interfaces.

Questions and answers:
['
Q: What does database access limit?
A: who (a person or a certain computer program) is allowed to access what information', '
Q: What are examples of database objects?
A: record types, specific records, data structures', '
Q: Who sets database access?
A: special authorized (by the database owner) personnel']
This may be managed directly on an individual basis, or by the assignment of individuals and privileges to groups, or (in the most elaborate models) through the assignment of individuals and groups to roles which are then granted entitlements. Data security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or subsets of it called "subschemas". For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data. If the DBMS provides a way to interactively enter and update the database, as well as interrogate it, this capability allows for managing personal databases.

Questions and answers:
['
Q: What does data security avoid?
A: unauthorized users from viewing or updating the database', '
Q: What is a subset of a database called that can be accessed by using a password?
A: subschemas', '
Q: What is possible when a DBMS interrogate and update a database?
A: managing personal databases']
Database transactions can be used to introduce some level of fault tolerance and data integrity after recovery from a crash. A database transaction is a unit of work, typically encapsulating a number of operations over a database (e.g., reading a database object, writing, acquiring lock, etc.), an abstraction supported in database and also other systems. Each transaction has well defined boundaries in terms of which program/code executions are included in that transaction (determined by the transaction's programmer via special transaction commands).

Questions and answers:
['
Q: What is a unit of work called in a database?
A: transaction', '
Q: Are transactions limited?
A: Each transaction has well defined boundaries', '
Q: How can database transactions ensure accuracy after a crash?
A: fault tolerance']
A database built with one DBMS is not portable to another DBMS (i.e., the other DBMS cannot run it). However, in some situations it is desirable to move, migrate a database from one DBMS to another. The reasons are primarily economical (different DBMSs may have different total costs of ownership or TCOs), functional, and operational (different DBMSs may have different capabilities). The migration involves the database's transformation from one DBMS type to another. The transformation should maintain (if possible) the database related application (i.e., all related application programs) intact. Thus, the database's conceptual and external architectural levels should be maintained in the transformation. It may be desired that also some aspects of the architecture internal level are maintained. A complex or large database migration may be a complicated and costly (one-time) project by itself, which should be factored into the decision to migrate. This in spite of the fact that tools may exist to help migration between specific DBMSs. Typically a DBMS vendor provides tools to help importing databases from other popular DBMSs.

Questions and answers:
['
Q: Why would someone attempt to unite two different databases?
A: primarily economical', '
Q: In order to merge, what must the database maintain?
A: database related application', '
Q: What are the important parts of the database related application that should be moved?
A: conceptual and external architectural levels', '
Q: How can a DBMS database migration be made easier?
A: vendor provides tools', '
Q: Can a DBMS be transfered to a different DBMS?
A: ano']
Sometimes it is desired to bring a database back to a previous state (for many reasons, e.g., cases when the database is found corrupted due to a software error, or if it has been updated with erroneous data). To achieve this a backup operation is done occasionally or continuously, where each desired database state (i.e., the values of its data and their embedding in database's data structures) is kept within dedicated backup files (many techniques exist to do this effectively). When this state is needed, i.e., when it is decided by a database administrator to bring the database back to this state (e.g., by specifying this state by a desired point in time when the database was in this state), these files are utilized to restore that state.

Questions and answers:
['
Q: Name a reason to take a database backward in time?
A: database is found corrupted', '
Q: Is each database backup kept in the same file?
A: dedicated backup files', '
Q: Who can restore a database that has been corrupted?
A: database administrator', '
Q: What parameter is requiret to restore a database?
A: desired point in time']
Static analysis techniques for software verification can be applied also in the scenario of query languages. In particular, the *Abstract interpretation framework has been extended to the field of query languages for relational databases as a way to support sound approximation techniques. The semantics of query languages can be tuned according to suitable abstractions of the concrete domain of data. The abstraction of relational database system has many interesting applications, in particular, for security purposes, such as fine grained access control, watermarking, etc.

Questions and answers:
['
Q: How can static analysis be useful with query languages?
A: software verification', '
Q: What do query languages support in abstract interpretation frameworks?
A: sound approximation techniques', '
Q: What is a security measure that uses a relational database system?
A: watermarking', '
Q: Can query languages be adjusted?
A: according to suitable abstractions of the concrete domain of data']
Tucson (/ˈtuːsɒn/ /tuːˈsɒn/) is a city and the county seat of Pima County, Arizona, United States, and home to the University of Arizona. The 2010 United States Census put the population at 520,116, while the 2013 estimated population of the entire Tucson metropolitan statistical area (MSA) was 996,544. The Tucson MSA forms part of the larger Tucson-Nogales combined statistical area (CSA), with a total population of 980,263 as of the 2010 Census. Tucson is the second-largest populated city in Arizona behind Phoenix, both of which anchor the Arizona Sun Corridor. The city is  located 108 miles (174 km) southeast of Phoenix and 60 mi (97 km) north of the U.S.-Mexico border. Tucson is the 33rd largest city and the 59th largest metropolitan area in the United States. Roughly 150 Tucson companies are involved in the design and manufacture of optics and optoelectronics systems, earning Tucson the nickname Optics Valley.

Questions and answers:
['
Q: What is the largest populated city in Arizona?
A: Phoenix', '
Q: How many miles is Tuscon from the U.S.- Mexico border?
A: 60', '
Q: What nickname does Tuscon have because of their many companies involved in optics?
A: Optics Valley', '
Q: What was the population of Tuscon according to the 2010 U.S. Census? 
A: 520,116', '
Q: What was the estimated population of the entire Tuscan area in 2013? 
A: 996,544', '
Q: Which county is Tucson in?
A: Pima County', '
Q: Which university is in Tucson?
A: University of Arizona', '
Q: How far is Tucson from Phoenix?
A: 108 miles (174 km)', '
Q: How far is Tucson from Mexico?
A: 60 mi (97 km)', '
Q: What industry-based nickname does Tucson have?
A: Optics Valley']
Tucson was probably first visited by Paleo-Indians, known to have been in southern Arizona about 12,000 years ago. Recent archaeological excavations near the Santa Cruz River have located a village site dating from 2100 BC.[citation needed] The floodplain of the Santa Cruz River was extensively farmed during the Early Agricultural period, circa 1200 BC to AD 150. These people constructed irrigation canals and grew corn, beans, and other crops while gathering wild plants and hunting. The Early Ceramic period occupation of Tucson saw the first extensive use of pottery vessels for cooking and storage. The groups designated as the Hohokam lived in the area from AD 600 to 1450 and are known for their vast irrigation canal systems and their red-on-brown pottery.[citation needed]

Questions and answers:
['
Q: What was Tuscon known as 12,000 years ago?
A: southern Arizona', '
Q: What group lived in the area that were known for their red-on-brown pottery?
A: Hohokam', '
Q: Near what river was a village site dating from 2100 BC found? 
A: Santa Cruz River', '
Q: Who were probably the first group of people in Tuscan?
A: Paleo-Indians', '
Q: How long ago did Tuscan have their first visitors?
A: 12,000 years ago', '
Q: How long ago were Paleo-Indians known to be in the Tucson area?
A: about 12,000 years ago', '
Q: How old was the village site found near the Santa Cruz River?
A: 2100 BC', '
Q: When was the Early Agricultural period?
A: 1200 BC to AD 150', '
Q: What happened in the Early Ceramic period?
A: the first extensive use of pottery vessels for cooking and storage', '
Q: When did the Hohokam live in the Tucson area?
A: from AD 600 to 1450']
Jesuit missionary Eusebio Francisco Kino visited the Santa Cruz River valley in 1692, and founded the Mission San Xavier del Bac in 1700 about 7 mi (11 km) upstream from the site of the settlement of Tucson. A separate Convento settlement was founded downstream along the Santa Cruz River, near the base of what is now "A" mountain. Hugo O'Conor, the founding father of the city of Tucson, Arizona authorized the construction of a military fort in that location, Presidio San Agustín del Tucsón, on August 20, 1775 (near the present downtown Pima County Courthouse). During the Spanish period of the presidio, attacks such as the Second Battle of Tucson were repeatedly mounted by Apaches. Eventually the town came to be called "Tucson" and became a part of Sonora after Mexico gained independence from Spain in 1821.

Questions and answers:
['
Q: What year did Mexico gain independence from Spain?
A: 1821', "
Q: Who is considered the founding father of Tuscan?
A: Hugo O'Conor", '
Q: Who founded the Mission San Xavier del Bac?
A: Eusebio Francisco Kino', '
Q: How many miles was Mission San Xavier del Bac from Tuscon?
A: 7', '
Q: Which missionary came to the Santa Cruz River area in 1692?
A: Eusebio Francisco Kino', '
Q: What religion was Kino?
A: Jesuit', '
Q: What mission did Kino found?
A: Mission San Xavier del Bac', '
Q: When did Kino found the del Bac mission?
A: 1700', "
Q: Who is Tucson's 'founding father'?
A: Hugo O'Conor"]