El Segundo is a city in Los Angeles County, United States. El Segundo, from Spanish, means "The Second". Located on the Santa Monica Bay, it was incorporated on January 18, 1917, part of the South Bay Cities Council of Governments; the population was 16,654 at the 2010 census up from 16,033 at the 2000 census. The El Segundo and Los Angeles coastal area was first settled by the Tongva Native American tribes thousands of years ago; the area was once a part of Rancho Sausal Redondo. Rancho Sausal Redondo extended from Playa Del Rey in the north to Redondo Beach in the south. A Mexican land grant owned by Antonio Ygnacio Avila, the rancho was purchased by a Scottish baronet named Sir Robert Burnett. After his return to Scotland, the property was purchased by then-manager of the rancho, Daniel Freeman. Daniel Freeman sold portions of the rancho to several persons. George H. Peck owned the 840 acres of land. Peck developed land in neighboring El Porto, where a street still bears his name; the city earned its name as it was the site of the second Standard Oil refinery on the West Coast, when Standard Oil of California purchased the farm land in 1911.

The city was incorporated in 1917. The Standard Oil Company was renamed Chevron in 1984; the El Segundo refinery entered its second century of operation in 2011. The Douglas Aircraft Company plant in El Segundo was one of the major aircraft manufacturing facilities in California during World War II, it was one of the major producers of SBD Dauntless dive bombers, which achieved fame in the Battle of Midway. The facility, now operated by Northrop Grumman, is still an aircraft plant; the north and south boundaries of the town are Los Angeles International Airport and Manhattan Beach, with the Pacific Ocean as the western boundary. Its eastern boundary is Aviation Blvd. El Segundo is located at 33°55′17″N 118°24′22″W. According to the United States Census Bureau, the city has a total area of 5.5 square miles, over 99% of, land. Guinness World Records has listed El Segundo as having the most roads with a grade; the 2010 United States Census reported that El Segundo had a population of 16,654. The population density was 3,047.9 people per square mile.

The racial makeup of El Segundo was 12,997 White, 337 African American, 68 Native American, 1,458 Asian, 38 Pacific Islander, 799 from other races, 957 from two or more races. Hispanics or Latinos of any race were 2,609 persons; the Census reported that 16,578 people lived in households, 66 lived in noninstitutionalized group quarters, 10 were institutionalized. Of the 7,085 households, 2,183 had children under the age of 18 living in them, 3,050 were married couples living together, 729 had a female householder with no husband present, 326 had a male householder with no wife present. About 31.8% were made up of individuals and 8.0% had someone living alone, 65 years of age or older. The average household size was 2.34. The city had 4,105 families. 22.3% of the population was under the age of 18, 6.7% was 18 to 24, 31.1% was 25 to 44, 29.8% was 45 to 64, 10.1%o was 65 or older. The median age was 39.2. For every 100 females, there were 99.4 males. For every 100 females 18 and over, there were 98.8 males.

The 7,410 housing units had an average density of 1,356.1 per square mile, of which 3,034 were owner-occupied and 4,051 occupied by renters. The homeowner vacancy rate was 0.4%. About 49.1% of the population lived in owner-occupied housing units and 50.4% in rental housing units. According to the 2010 United States Census, El Segundo had a median household income of $84,341, with 4.8% of the population living below the federal poverty line. As of the 2000 Census, the population density was 2,894.6 inhabitants per square mile. There were 7,261 housing units at an average density of 1,310.9 per square mile. The racial makeup of the city was 83.61% White, 1.17% African American, 0.47% Native American, 6.41% Asian, 0.29% Pacific Islander, 3.51% from other races, 4.55% from two or more races. Hispanics or Latinos of any race were 11.01% of the population. Of the 7,060 households, 28.1% had children under the age of 18 living with them, 41.5% were married couples living together, 10.0% had a female householder with no husband present, 44.6% were not families.

Of all households, 34.3% were made up of individuals and 7.5% had someone living alone, 65 years of age or older. The average household size was 2.27 and the average family size was 3.00. 22.7% of the population was under age 18, 6.2% from 18 to 24, 38.7% from 25 to 44, 22.9% from 45 to 64, 9.5% 65 or older. The median age was 36. For every 100 females, there were 98.7 males. For every 100 females 18 and over, there were 96.0 males. The median income for a household in the city was $61,341, for a family was $74,007. Males had a median income of $52,486 versus $41,682 for females; the per capita income for the city was $33,996. About 3.1% of families and 4.6% of the population were below the poverty line, including 4.7% of those under age 18 and 6.0% of those age 65 or over. El Segundo has many petroleum-related industries and operations. In 2006, it won an Eddy award for being the most business-friendly city in L. A. County; the name was adopted i

In software engineering, schema migration refers to the management of incremental, reversible changes and version control to relational database schemas. A schema migration is performed on a database whenever it is necessary to update or revert that database's schema to some newer or older version. Migrations are performed programmatically by using a schema migration tool; when invoked with a specified desired schema version, the tool automates the successive application or reversal of an appropriate sequence of schema changes until it is brought to the desired state. Most schema migration tools aim to minimize the impact of schema changes on any existing data in the database. Despite this, preservation of data in general is not guaranteed because schema changes such as the deletion of a database column can destroy data. Instead, the tools help to preserve the meaning of the data or to reorganize existing data to meet new requirements. Since meaning of the data cannot be encoded, the configuration of the tools needs manual intervention.

Schema migration allows for adapting the data as requirements change. They are an essential part of software evolution in agile environments. Applying a schema migration to a production database is always a risk. Development and test databases tend to be cleaner; the data in them is better understood or, if everything else fails, the amount of data is small enough for a human to process. Production databases are huge and full of surprises; the surprises can come from many sources: Corrupt data, written by old versions of the software and not cleaned properly Implied dependencies in the data which no one knows about anymore People directly changing the database without using the designated tools Bugs in the schema migration tools Mistakes in assumptions how data should be migratedFor these reasons, the migration process needs a high level of discipline, thorough testing and a sound backup strategy. When developing software applications backed by a database, developers develop the application source code in tandem with an evolving database schema.

The code has rigid expectations of what columns and constraints are present in the database schema whenever it needs to interact with one, so only the version of database schema against which the code was developed is considered compatible with that version of source code. In software testing, while developers may mock the presence of a compatible database system for unit testing, any level of testing higher than this it is common for developers to test their application against a local or remote test database schematically compatible with the version of source code under test. In advanced applications, the migration itself can be subject to migration testing. With schema migration technology, data models no longer need to be designed up-front, are more capable of being adapted with changing project requirements throughout the software development lifecycle. Teams of software developers use version control systems to manage and collaborate on changes made to versions of source code. Different developers can develop on divergent older or newer branches of the same source code to make changes and additions during development.

Supposing that the software under development interacts with a database, every version of the source code can be associated with at least one database schema with which it is compatible. Under good software testing practice, schema migrations can be performed on test databases to ensure that their schema is compatible to the source code. To streamline this process, a schema migration tool is invoked as a part of an automated software build as a prerequisite of the automated testing phase. Schema migration tools can be said to solve versioning problems for database schemas just as version control systems solve versioning problems for source code. In practice, many schema migration tools rely on a textual representation of schema changes such that the version history of schema changes can be stored alongside program source code within VCS; this approach ensures that the information necessary to recover a compatible database schema for a particular code branch is recoverable from the source tree itself.

Another benefit of this approach is the handling of concurrent conflicting schema changes. Schema migration tooling could be seen as a facility to track the history of an evolving schema. Developers no longer need to remove the entire test database in order to create a new test database from scratch. Further, if generation of test data costs a lot of time, developers can avoid regenerating test data for small, non-destructive changes to the schema. Martin Fowler: Evolutionary Database Design Active Record Migrations

David L. Hallal is the former President and Chief Executive Officer of Alexion Pharmaceuticals, the American pharmaceutical company best known for its development of Soliris, a drug used to treat the rare disorders atypical hemolytic uremic syndrome and paroxysmal nocturnal hemoglobinuria. From 1992 to 2002 Hallal worked at Amgen, the world's largest independent, biopharmaceutical, biotechnology firm. While at Amgen, Hallal focused on Amgen's blockbuster brands Epoetin alfa and Filgrastim and Darbepoetin alfa in the hematology and oncology marketplace, in various escalating leadership positions. During that time he forged "relationships with many of the largest managed care organizations in the U. S." As Amgen's Director of Oncology National Accounts in 1998 and 1999 he "played a significant role in developing key long-term partnerships with the nation's largest oncology practice management groups and physician group purchasing organizations."From 1999 to 2002, he was Sales Director of Southeast Oncology during which time he helped Amgen build its first dedicated hospital sales team.

By 2006 Amgen's Epogen and Aranesp—Epogen's longer-lasting version known as Darbepoetin alfa, a synthetic form of erythropoietin— "combined generated an annual worldwide sales of $6.6 billion. From August 2002 to February 2004, he was "Senior Director of Sales for Biogen Idec's Immunology Sales Team, where he built a sales organization dedicated to the launch of the first-in-class biologic Alefacept indicated for adults with chronic plaque psoriasis; the manufacturer ceased to market Amevive in 2011 for market reasons. From April 2004 to June 2006 he was Vice President of Sales at OSI Eyetech. In 2000 EyeTech Pharmaceuticals acquired the license to pegaptanib, a first-in-class anti-VEGF, anti-angiogenic therapy for the treatment of neovascular age-related macular degeneration. OSI did the late stage development and marketing in the United States for Macugen and Hallal led the U. S. launch of Macugen. In 2006 Hallal became Alexion's Vice President U. S. Commercial Operations reporting to then-President and CEO David Keiser with the mandate to "direct the expected launch of Soliris in the United States.

Hallal was responsible "for all U. S. commercial operations including sales, marketing and corporate account management, customer relations." In 2014 his total annual compensation was USD$696,058. Starting in November 2008 Hallal was Senior Vice President of Commercial Operations. Starting in May 2010 he was Senior Vice President of Global Commercial Operations, responsible for all commercial functions in the U. S. market, including marketing and reimbursement/access. From October 2012 to September 2014 he was Executive Vice President. In September 2014 he became a Director. In September 2016 he owned 190 thousand Alexion Pharmaceuticals shares worth of US$25 million. On November 9, 2016, Alexion Pharmaceuticals announced that an Audit and Finance Committee was investigating the Company's sales practices related to Soliris; the investigation resulted in the delayed filing of Alexion's third quarter report with the Securities and Exchange Commission. On December 12, 2016, along with Alexion's Chief Financial Officer Vikas Sinha, resigned from Alexion citing personal reasons