简单的jdbc queryForList需要大约3秒才能执行

Question

title=jdbcTemplate.queryForList("SELECT distinct title from UD_REGGRESSION where delete_flag='N'",String.class);

上述查询大约需要3到4秒才能执行，只提取了21条记录。在Toad中，执行相同的查询大约需要500到600毫秒。为什么时间上有这么大的差异？

类已完成配置。

@Configuration
@ConfigurationProperties(prefix = "oracle")
public class OracleConfiguration {
    @NotNull
    private String username;
    @NotNull
    private String password;
    @NotNull
    private String url;
    @NotNull
    private String decryptionKey;

    public String getDecryptionKey() {
        return decryptionKey;
    }

    public void setDecryptionKey(String decryptionKey) {
        this.decryptionKey = decryptionKey;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getUsername() {
        return username;
    }

    public String getPassword() {
        return password;
    }

    public String getUrl() {
        return url;
    }

    @Bean
    public DataSource dataSource() throws SQLException {

        OracleDataSource dataSource = new OracleDataSource();
        dataSource.setUser(username);
        dataSource.setPassword(password);
        dataSource.setURL(url);
        dataSource.setImplicitCachingEnabled(true);
        dataSource.setFastConnectionFailoverEnabled(true);
        return dataSource;
    }

    @PostConstruct
    public void decrypt() {
        this.password = DecryptUtility.decrypt(this.password,
                this.decryptionKey);
    }
}

有人建议可以采取哪些改进措施来获得更好的响应时间吗？